Repository: go
Issue: x/tools/gopls: picks random import path not in go.mod when wanted import path for package is in go.mod
Labels: NeedsFix,gopls,Tools,gopls/imports

### What version of Go, VS Code & VS Code Go extension are you using?
<details><summary>Version Information</summary><br>

* Run `go version` to get version of Go from _the VS Code integrated terminal_.
	- `go version go1.20.5 darwin/arm64`
* Run `gopls -v version` to get version of Gopls from _the VS Code integrated terminal_.
	- `golang.org/x/tools/gopls v0.12.4`
* Run `code -v` or `code-insiders -v` to get version of VS Code or VS Code Insiders.
	- `1.79.2`
* Check your installed extensions to get the version of the VS Code Go extension
	- `v0.39.0`
* Run Ctrl+Shift+P (Cmd+Shift+P on Mac OS) > `Go: Locate Configured Go Tools` command.

```
Checking configured tools....
GOBIN: undefined
toolsGopath: 
gopath: /Users/meling/go
GOROOT: /opt/homebrew/Cellar/go/1.20.5/libexec
PATH: /opt/homebrew/bin:/opt/homebrew/sbin:/usr/local/bin:/System/Cryptexes/App/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/local/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/bin:/var/run/com.apple.security.cryptexd/codex.system/bootstrap/usr/appleinternal/bin:/Users/meling/.cargo/bin:/Users/meling/go/bin

	go:	/opt/homebrew/bin/go: go version go1.20.5 darwin/arm64

	gotests:	/Users/meling/go/bin/gotests	(version: v1.6.0 built with go: go1.20.3)
	gomodifytags:	/Users/meling/go/bin/gomodifytags	(version: v1.16.0 built with go: go1.20.3)
	impl:	/Users/meling/go/bin/impl	(version: v1.1.0 built with go: go1.20.3)
	goplay:	/Users/meling/go/bin/goplay	(version: v1.0.0 built with go: go1.20.3)
	dlv:	/Users/meling/go/bin/dlv	(version: v1.20.1 built with go: go1.20.3)
	golangci-lint:	/Users/meling/go/bin/golangci-lint	(version: v1.51.0 built with go: go1.20.3)
	gopls:	/Users/meling/go/bin/gopls	(version: v0.12.4 built with go: go1.20.5)

go env
Workspace Folder (hotstuff): /Users/meling/Team-UIS Dropbox/Hein Meling/work/hotstuff
	GO111MODULE=""
	GOARCH="arm64"
	GOBIN=""
	GOCACHE="/Users/meling/Library/Caches/go-build"
	GOENV="/Users/meling/Library/Application Support/go/env"
	GOEXE=""
	GOEXPERIMENT=""
	GOFLAGS=""
	GOHOSTARCH="arm64"
	GOHOSTOS="darwin"
	GOINSECURE=""
	GOMODCACHE="/Users/meling/go/pkg/mod"
	GONOPROXY=""
	GONOSUMDB=""
	GOOS="darwin"
	GOPATH="/Users/meling/go"
	GOPRIVATE=""
	GOPROXY="https://proxy.golang.org,direct"
	GOROOT="/opt/homebrew/Cellar/go/1.20.5/libexec"
	GOSUMDB="sum.golang.org"
	GOTMPDIR=""
	GOTOOLDIR="/opt/homebrew/Cellar/go/1.20.5/libexec/pkg/tool/darwin_arm64"
	GOVCS=""
	GOVERSION="go1.20.5"
	GCCGO="gccgo"
	AR="ar"
	CC="/opt/homebrew/bin/gcc-13"
	CXX="/opt/homebrew/bin/g++-13"
	CGO_ENABLED="1"
	GOMOD="/Users/meling/Team-UIS Dropbox/Hein Meling/work/hotstuff/go.mod"
	GOWORK=""
	CGO_CFLAGS="-O2 -g"
	CGO_CPPFLAGS=""
	CGO_CXXFLAGS="-O2 -g"
	CGO_FFLAGS="-O2 -g"
	CGO_LDFLAGS="-O2 -g"
	PKG_CONFIG="pkg-config"
	GOGCCFLAGS="-fPIC -arch arm64 -pthread -fmessage-length=0 -fdebug-prefix-map=/var/folders/gl/s8cqs8k12kdgvgplr56lz3q40000gn/T/go-build2039093197=/tmp/go-build -gno-record-gcc-switches -fno-common"
```
</details>

### Share the Go related settings you have added/edited

Run `Preferences: Open Settings (JSON)` command to open your settings.json file.
Share all the settings with the `go.` or `["go"]` or `gopls` prefixes.

<details><summary>Excerpt from settings.json</summary><br>

```json
    "go.useLanguageServer": true,
    "go.languageServerFlags": [
        "-rpc.trace"
    ],
    "go.toolsManagement.autoUpdate": true,
    "go.toolsEnvVars": {
        "CXX": "/opt/homebrew/bin/g++-13",
        "CC": "/opt/homebrew/bin/gcc-13",
    },
    "gopls": {
        "build.standaloneTags": [
            "tools",
            "ignore"
        ],
        "formatting.gofumpt": true,
        "build.env": {
            "CXX": "/opt/homebrew/bin/g++-13",
            "CC": "/opt/homebrew/bin/gcc-13",
        },
        "verboseOutput": true
    },
```

</details>

### Describe the bug

When starting to use a new package in a Go source file, the plugin (automatically) adds an import path to an identically named package that is not available in my `go.mod` file. This happens even though my project is already using the package/import path I want in other files (and thus is already in my `go.mod`). That is, the plugin is not able to recognize an existing import path for the package, but instead appears to pick an import path at random.

I would expect that the plugin would prioritize to use the import path of the package already available in `go.mod`.

### Steps to reproduce the behavior:
1. Write a new function that returns a `proto.Message` type.
2. Save the file.
3. Watch the import section be augmented with `"go.starlark.net/lib/proto"`
4. Run `grep -R 'go.starlark.net/lib/proto' *` and observe that the entire project makes no mention of this import path.
5. Run `grep -R 'google.golang.org/protobuf/proto' * | wc -l` and observe that the project is using this import path in 11 files.
6. See screenshots below

### Screenshots or recordings

<img width="753" alt="Screenshot 2023-06-29 at 13 33 55" src="https://github.com/golang/vscode-go/assets/810999/6893566a-9b70-43ad-9e9c-58126fa13f8d">
<img width="525" alt="Screenshot 2023-06-29 at 13 33 19" src="https://github.com/golang/vscode-go/assets/810999/6f66ad87-7e4e-41fb-946b-ecc539035e1b">