refactor(core)!: replace workspace.dependencies with worskpace.anchoredPackage

[paul-soporan]

What's the problem this PR addresses?

I don't like workspace.dependencies because the Project class has to manually keep it in sync (and historically it hasn't done a good job).

How did you fix it?

I removed it and added a new workspace.anchoredPackage getter that can be used in more situations.

Since there is only one production codepath using workspace.dependencies and it accesses it a single time, the lack of caching for workspace.anchoredPackage doesn't affect its performance.

Checklist

• I have read the Contributing Guide.

• I have set the packages that need to be released for my changes to be effective.

• I will check that all automated PR checks pass before the PR gets reviewed.

[arcanis]

API-wise, what about turning it into a getter named anchoredPackage? It'd nicely mirror the existing anchoredLocator 🤔

[paul-soporan]

I like this idea, even though I generally don't like getters.
Since in this case workspace.anchoredPackage is O(1) anyways, it doesn't really hide expensive computations, and we already have other such getters (project.topLevelWorkspace), so it's fine by me (especially since it nicely mirrors workspace.anchoredLocator as you said).

I've updated the PR 👍