Migrate CI to GitHub Actions

[emilykl]

Link to issue

Closes #5239

Description of change

Migrate remaining CircleCI workflows to GitHub Actions.

All existing jobs/steps/workflows have been migrated, EXCEPT for the Build HTML figures (Pandas 1) and compare step in the Percy workflow. This test was failing on GHA due to some small floating-point differences between Numpy 1 and 2, and I don't think it's a very relevant test anymore, so I just decided to remove it entirely.

Demo

N/A

Testing strategy

Check that all CI jobs are passing and manually verify that all workflow steps have been migrated.

Additional information (optional)

Guidelines

• I have reviewed the pull request guidelines and the Code of Conduct and confirm that this PR follows them.
• I have added an entry to the changelog if needed (not required for documentation PRs).

[emilykl]

@camdecoster FYI I believe these "pending" old CircleCI checks are showing up due to the "Require status checks to pass before merging" rule for main.

Once this PR is merged, we can update that rule and those old checks should stop showing up.

[camdecoster]

I left a few comments about structure, but this looks fine to me.

[camdecoster]

There's an official Astral action to install uv which might be a better option.

[emilykl]

Oh good tip, we should probably use that one then.

[camdecoster]

You could use a composite action to handle the browser set up.

[emilykl]

I actually did, but forgot to update this usage here. Thanks!