Failure in `gitlab-org:stage-and-group-labels-hygiene`

Job [#519421583](https://gitlab.com/gitlab-org/quality/triage-ops/-/jobs/519421583) failed for 1dff6a9bb586b085772b21f3a94a0caafaf2c46b:

```
 .[DEBUG] query_api: https://gitlab.com/api/v4/groups/9970/issues?per_page=100&state=opened&page=390/builds/gitlab-org/quality/triage-ops/lib/devops_labels.rb:330:in `group_part_of_stage?': undefined method `include?' for nil:NilClass (NoMethodError)
 	from /builds/gitlab-org/quality/triage-ops/lib/devops_labels.rb:383:in `inference_strategy_for_merge_request'
 	from /builds/gitlab-org/quality/triage-ops/lib/devops_labels.rb:420:in `infer_new_labels'
 	from /builds/gitlab-org/quality/triage-ops/lib/devops_labels.rb:351:in `new_stage_and_group_labels_from_intelligent_inference'
 	from /builds/gitlab-org/quality/triage-ops/lib/devops_labels.rb:355:in `comment_for_intelligent_stage_and_group_labels_inference'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/resource/context.rb:24:in `eval'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/resource/context.rb:22:in `instance_eval'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/resource/context.rb:22:in `eval'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/command_builders/text_content_builder.rb:65:in `eval_interpolation'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/command_builders/text_content_builder.rb:55:in `format_item'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/command_builders/base_command_builder.rb:30:in `block in content_string'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/command_builders/base_command_builder.rb:29:in `map'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/command_builders/base_command_builder.rb:29:in `content_string'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/command_builders/base_command_builder.rb:12:in `build_command'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action/comment.rb:42:in `build_comment'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action/comment.rb:31:in `block in act'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/policies_resources/rule_resources.rb:15:in `block in each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/policies_resources/rule_resources.rb:14:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/policies_resources/rule_resources.rb:14:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action/comment.rb:30:in `act'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action.rb:24:in `act'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action.rb:12:in `block in process'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action.rb:11:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/action.rb:11:in `process'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:178:in `process_action'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:115:in `block (2 levels) in process_rules'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:167:in `block in resources_for_rule'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/expand_condition.rb:13:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/expand_condition.rb:13:in `perform'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:151:in `resources_for_rule'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:111:in `block in process_rules'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:110:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:110:in `process_rules'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:57:in `block in perform'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:52:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/lib/gitlab/triage/engine.rb:52:in `perform'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/bin/gitlab-triage:15:in `block in <top (required)>'
 	from /usr/local/lib/ruby/2.6.0/set.rb:338:in `each_key'
 	from /usr/local/lib/ruby/2.6.0/set.rb:338:in `each'
 	from /usr/local/bundle/gems/gitlab-triage-1.7.1/bin/gitlab-triage:10:in `<top (required)>'
 	from /usr/local/bundle/bin/gitlab-triage:23:in `load'
 	from /usr/local/bundle/bin/gitlab-triage:23:in `<main>'
```

Story points: 2.0