Upload conda packages for rapids_core_dependencies.

[bdice]

Description

This PR uploads conda packages as CI artifacts for rapids_core_dependencies.

I also aligned some bits of rapids-cmake's testing scripts/workflows with other RAPIDS repos.

Checklist

• I am familiar with the Contributing Guidelines.
• New or existing tests cover these changes.
• The documentation is up to date with these changes.
• The cmake-format.json is up to date with these changes.
• I have added new files under rapids-cmake/
  • I have added include guards (include_guard(GLOBAL))
  • I have added the associated docs/ rst file and update the api.rst

[ajschmidt8]

Do these builds/tests need to occur nightly?

If so, we'll need to add rapids-cmake to the nightly pipeline below:

• https://github.com/rapidsai/actions/blob/main/.github/workflows/nightly-pipeline.yaml

[vyasr]

I don't have a strong opinion on whether we run the tests nightly, but since we have the infra in place I think we might as well.

[bdice]

/merge