Use $(location ) to set env var in .bazelrc

### Description of the bug:

**Description of the bug:**
We'd like to set an environment variable (e.g. `--test_env`) pointing to an artifact which is part of a bazel module
currently this can be done by setting it as a relative path to `external//path/to/artifact`
But lacks maintainability.

A better solution would be to set it to `($location @@modules_repo_name//:SomeTarget)`

Currently this results in an error like this (from the example below):
```
ERROR: no such target '@@rules_license+//:LICENSE)': target 'LICENSE)' not declared in package '' defined by /home/q476994/.cache/bazel/_bazel_q476994/29ce9988bdb091793566352b41ee3f8e/external/rules_license+/BUILD (did you mean LICENSE, or license?)
```

Note: The actual use case is pointing to a coverage tool executable

### Which category does this issue belong to?

Configurability, Core

### What's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

https://github.com/iancanadell-bmw/make_vars_bazelrc
`bazel test //...:all`

### Which operating system are you running Bazel on?

Ubuntu 2204 on WSL

### What is the output of `bazel info release`?

release: release 8.0.1; But also present in 7.1.2

### If `bazel info release` returns `development version` or `(@non-git)`, tell us how you built Bazel.

_No response_

### What's the output of `git remote get-url origin; git rev-parse HEAD` ?

```text
see minimal example above
```
:smile:

### If this is a regression, please try to identify the Bazel commit where the bug was introduced with bazelisk --bisect.

_No response_

### Have you found anything relevant by searching the web?

No

### Any other information, logs, or outputs that you want to share?

Maybe not really a bug. But then it would be a feature request

Start with the linked minimal example and its .bazelrc, then run `bazel test //...:all` on Bazel 7.1.2 or 8.0.1 to reproduce the `--test_env` location expansion error. Done means a module artifact can be referenced through `$(location ...)` in `.bazelrc` without the target name being parsed incorrectly.

Written by the indexing model from the issue text.