Failed to upgrade to 1.3.0 with error "admission webhook sgscripts.stackgres.stackgres denied the request: SGScript has invalid properties."

### Summary

When upgrading from v1.2.1 to v1.3.0 using the helm chart, the stackgres-cr-updater job fails with the following error: `admission webhook sgscripts.stackgres.stackgres denied the request: SGScript has invalid properties`.

I also attached the SGCluster resource below.

### Environment

- StackGres version: v1.3.0 (upgraded from v1.2.1; also tested from v1.1.0)
- Kubernetes version: v1.21.9
- Cloud provider or hardware configuration: Kubernetes cluster installed with Rancher and using RancherOS

### Relevant logs and/or screenshots

stackgres-cr-updater job logs:

```
2022-08-31 09:09:07,021 INFO  [io.quarkus] (main) stackgres-jobs 1.3.0 native (powered by Quarkus 2.11.2.Final) started in 0.077s. Listening on: http://0.0.0.0:8080
2022-08-31 09:09:07,026 INFO  [io.quarkus] (main) Profile prod activated. 
2022-08-31 09:09:07,026 INFO  [io.quarkus] (main) Installed features: [cdi, hibernate-validator, kubernetes-client, smallrye-context-propagation, vertx]
2022-08-31 09:09:07,235 INFO  [io.st.jo.cr.CrUpdaterImpl] (main) Patching existing custom resources to apply defaults for CRD SGBackup
2022-08-31 09:09:07,411 INFO  [io.st.jo.cr.CrUpdaterImpl] (main) Existing custom resources for CRD SGBackup. Patched
2022-08-31 09:09:07,411 INFO  [io.st.jo.cr.CrUpdaterImpl] (main) Patching existing custom resources to apply defaults for CRD SGBackupConfig
2022-08-31 09:09:07,595 INFO  [io.st.jo.cr.CrUpdaterImpl] (main) Existing custom resources for CRD SGBackupConfig. Patched
2022-08-31 09:09:07,595 INFO  [io.st.jo.cr.CrUpdaterImpl] (main) Patching existing custom resources to apply defaults for CRD SGCluster
2022-08-31 09:09:07,750 ERROR [io.qu.ru.Application] (main) Failed to start application (with profile prod): io.fabric8.kubernetes.client.KubernetesClientException: Failure executing: PUT at: https://10.43.0.1/apis/stackgres.io/v1/namespaces/bar-304-k8sapps-stag-r1az-zbgais/sgclusters/bar-foo-bar-pg. Message: admission webhook "sgcluster.stackgres.stackgres" denied the request: Failure executing: POST at: https://10.43.0.1/apis/stackgres.io/v1/namespaces/bar-304-k8sapps-stag-r1az-zbgais/sgscripts. Message: admission webhook "sgscripts.stackgres.stackgres" denied the request: SGScript has invalid properties. secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required.. Received status: Status(apiVersion=v1, code=422, details=StatusDetails(causes=[StatusCause(field=spec.scripts[0].scriptFrom.configMapKeyRef, message=secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required., reason=javax.validation.constraints.AssertTrue, additionalProperties={}), StatusCause(field=spec.scripts[0].scriptFrom.secretKeyRef, message=secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required., reason=javax.validation.constraints.AssertTrue, additionalProperties={})], group=null, kind=null, name=null, retryAfterSeconds=null, uid=null, additionalProperties={}), kind=Status, message=admission webhook "sgscripts.stackgres.stackgres" denied the request: SGScript has invalid properties. secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required., metadata=ListMeta(_continue=null, remainingItemCount=null, resourceVersion=null, selfLink=null, additionalProperties={}), reason=https://stackgres.io/doc/1.3/api/responses/error#constraint-violation, status=Failure, additionalProperties={}).. Received status: Status(apiVersion=v1, code=500, details=null, kind=Status, message=admission webhook "sgcluster.stackgres.stackgres" denied the request: Failure executing: POST at: https://10.43.0.1/apis/stackgres.io/v1/namespaces/bar-304-k8sapps-stag-r1az-zbgais/sgscripts. Message: admission webhook "sgscripts.stackgres.stackgres" denied the request: SGScript has invalid properties. secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required.. Received status: Status(apiVersion=v1, code=422, details=StatusDetails(causes=[StatusCause(field=spec.scripts[0].scriptFrom.configMapKeyRef, message=secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required., reason=javax.validation.constraints.AssertTrue, additionalProperties={}), StatusCause(field=spec.scripts[0].scriptFrom.secretKeyRef, message=secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required., reason=javax.validation.constraints.AssertTrue, additionalProperties={})], group=null, kind=null, name=null, retryAfterSeconds=null, uid=null, additionalProperties={}), kind=Status, message=admission webhook "sgscripts.stackgres.stackgres" denied the request: SGScript has invalid properties. secretKeyRef and configMapKeyRef are mutually exclusive and one of them is required., metadata=ListMeta(_continue=null, remainingItemCount=null, resourceVersion=null, selfLink=null, additionalProperties={}), reason=https://stackgres.io/doc/1.3/api/responses/error#constraint-violation, status=Failure, additionalProperties={})., metadata=ListMeta(_continue=null, remainingItemCount=null, resourceVersion=null, selfLink=null, additionalProperties={}), reason=null, status=Failure, additionalProperties={}).
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.requestFailure(OperationSupport.java:684)
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.requestFailure(OperationSupport.java:664)
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.assertResponseCode(OperationSupport.java:615)
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:558)
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleResponse(OperationSupport.java:521)
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleUpdate(OperationSupport.java:345)
	at io.fabric8.kubernetes.client.dsl.base.OperationSupport.handleUpdate(OperationSupport.java:325)
	at io.fabric8.kubernetes.client.dsl.base.BaseOperation.handleUpdate(BaseOperation.java:649)
	at io.fabric8.kubernetes.client.dsl.base.HasMetadataOperation.lambda$replace$1(HasMetadataOperation.java:195)
	at io.fabric8.kubernetes.client.dsl.base.HasMetadataOperation.replace(HasMetadataOperation.java:200)
	at io.fabric8.kubernetes.client.dsl.base.HasMetadataOperation.replace(HasMetadataOperation.java:141)
	at io.fabric8.kubernetes.client.dsl.base.HasMetadataOperation.replace(HasMetadataOperation.java:43)
	at io.stackgres.jobs.crdupgrade.CrdLoaderImpl.lambda$updateExistingCustomResources$1(CrdLoaderImpl.java:93)
	at io.stackgres.common.kubernetesclient.KubernetesClientUtil.lambda$retryOnConflict$0(KubernetesClientUtil.java:29)
	at io.stackgres.common.kubernetesclient.KubernetesClientUtil.retryOnConflict(KubernetesClientUtil.java:41)
	at io.stackgres.common.kubernetesclient.KubernetesClientUtil.retryOnConflict(KubernetesClientUtil.java:28)
	at io.stackgres.jobs.crdupgrade.CrdLoaderImpl.lambda$updateExistingCustomResources$2(CrdLoaderImpl.java:83)
	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)
	at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
	at io.stackgres.jobs.crdupgrade.CrdLoaderImpl.updateExistingCustomResources(CrdLoaderImpl.java:82)
	at io.stackgres.jobs.crdupgrade.CrUpdaterImpl.lambda$updateExistingCustomResources$0(CrUpdaterImpl.java:28)
	at java.util.AbstractList$RandomAccessSpliterator.forEachRemaining(AbstractList.java:720)
	at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)
	at io.stackgres.jobs.crdupgrade.CrUpdaterImpl.updateExistingCustomResources(CrUpdaterImpl.java:25)
	at io.stackgres.jobs.Main.run(Main.java:77)
	at io.stackgres.jobs.Main_ClientProxy.run(Unknown Source)
	at io.quarkus.runtime.ApplicationLifecycleManager.run(ApplicationLifecycleManager.java:129)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:67)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:41)
	at io.quarkus.runner.GeneratedMain.main(Unknown Source)

2022-08-31 09:09:07,753 INFO  [io.st.co.ku.KubernetesClientProducer] (main) Closing instance of StackGresKubernetesClient
2022-08-31 09:09:07,759 INFO  [io.quarkus] (main) stackgres-jobs stopped in 0.008s
```

SGCluster resource (as retrieved after the failed upgrade) :

```
apiVersion: stackgres.io/v1
kind: SGCluster
metadata:
  annotations:
    meta.helm.sh/release-name: bar
    meta.helm.sh/release-namespace: bar-304-k8sapps-stag-r1az-zbgais
    stackgres.io/operatorVersion: 1.1.0
  creationTimestamp: "2022-03-10T12:37:59Z"
  generation: 3
  labels:
    app.kubernetes.io/managed-by: Helm
  name: bar-foo-bar-pg
  namespace: bar-304-k8sapps-stag-r1az-zbgais
  resourceVersion: "102373195"
  uid: 898fa701-1c72-4494-8be1-f4e9f3fc8bae
spec:
  configurations:
    sgPoolingConfig: generated-from-default-1646915879796
    sgPostgresConfig: postgres-13-generated-from-default-1646915879718
  initialData:
    scripts:
    - name: create-users
      scriptFrom:
        secretKeyRef:
          key: INIT_CREATE_USERS
          name: bar-foo-bar-pg
    - name: create-db
      script: CREATE DATABASE app OWNER app
    - name: grant-user-db
      script: GRANT ALL PRIVILEGES ON DATABASE app TO graphql;
  instances: 2
  pods:
    persistentVolume:
      size: 1Gi
      storageClass: openebs-zfs
  postgres:
    extensions: []
    flavor: vanilla
    ssl:
      certificateSecretKeySelector:
        key: tls.crt
        name: bar-foo-bar-selfsigned-pg
      enabled: true
      privateKeySecretKeySelector:
        key: tls.key
        name: bar-foo-bar-selfsigned-pg
    version: "13.5"
  postgresServices:
    primary:
      enabled: true
      type: ClusterIP
    replicas:
      enabled: true
      type: ClusterIP
  replication:
    mode: async
    role: ha-read
  sgInstanceProfile: bar-foo-bar-pg
  toInstallPostgresExtensions: []
status:
  arch: x86_64
  conditions:
  - lastTransitionTime: "2022-03-10T12:38:03.198048Z"
    reason: FalseFailed
    status: "False"
    type: Failed
  - lastTransitionTime: "2022-08-19T11:39:43.822677Z"
    reason: ClusterRequiresUpgrade
    status: "True"
    type: PendingUpgrade
  - lastTransitionTime: "2022-08-31T09:02:45.311942Z"
    reason: FalsePendingRestart
    status: "False"
    type: PendingRestart
  labelPrefix: ""
  os: linux
  podStatuses:
  - installedPostgresExtensions: []
    name: bar-foo-bar-pg-1
    pendingRestart: false
    replicationGroup: 1
  - installedPostgresExtensions: []
    name: bar-foo-bar-pg-0
    pendingRestart: false
    replicationGroup: 0
```

Story points: 4.0