Bump GitHub actions versions (backport #2503)

[mergify]

Description

actions/checkout@v4 uses Node 20, which will be removed from GitHub runners in 4 days:
https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Is this user-facing behavior change?

Did you use Generative AI?

Additional Information

Should probably be backported to all active distro branches.

---

This is an automatic backport of pull request #2503 done by Mergify.

[mergify]

Cherry-pick of 308aa80 has failed:

On branch mergify/bp/jazzy/pr-2503
Your branch is up to date with 'origin/jazzy'.

You are currently cherry-picking commit 308aa80.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   .github/workflows/test.yml

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   .github/workflows/lint.yml

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally