Prefer cache entries written by dependent jobs

Currently, when retrieving Gradle User Home state, we look for a cache entry written by an earlier execution of the same Job. If not found, we revert to searching for the most recent cache entry written by any Job on the same OS.

An optimization to this would be to prefer an entry written by a dependent Job (as defined by the [needs context](https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs#needs-context)) over an entry written by a different, arbitrary Job.

We would search for cache entries as follows:

```
1) An exact match on OS, job id, workflow name, matrix, and Git SHA
2) The most recent entry saved for the same OS, job id, workflow name, and matrix values
3) The most recent entry saved for the same OS and job id
NEW 4) The most recent entry saved for a dependent job on the same OS
5) The most recent entry saved for the same OS
```

Start by tracing the Gradle User Home cache-retrieval path and how the existing five search priorities are implemented. Use the linked needs context documentation to determine dependent jobs; done means the most recent same-OS cache from a dependent job is considered before the general same-OS fallback.

Written by the indexing model from the issue text.