Adjust gazelle for upcoming rules_go changes

[dzbarsky]

What type of PR is this?
Code refactor/future-proofing

What package or component does this PR mostly affect?
gazelle binary

What does this PR do? Why is it needed?

• rules_go is deprecating some attributes from go_context (such as package_list), so stop using it.
• binaries should not return the library/source provider so they cannot be accidentally used as deps/embed in other rules
• I am also considering revamping how runfiles collection works in rules_go, so we can just collect the runfiles from languages directly to insulate ourselves from future changes there.

Which issues(s) does this PR fix?

Fixes #

Other notes for review

[fmeum]

Can we make it so that this works with both the current and the upcoming version of rules_go? It wouldn't matter for Bzlmod, but WORKSPACE users will have an easier time updating if that's the case.

[dzbarsky]

Can we make it so that this works with both the current and the upcoming version of rules_go? It wouldn't matter for Bzlmod, but WORKSPACE users will have an easier time updating if that's the case.

The rules_go changes don't break gazelle, we can land this future-proofing after the release is cut.

Edit:except the binary providers. Hmmm...