[hakshu25]

Why

GitHub removed Node.js 20 from the hosted runners on September 23, 2026 (changelog). Our workflows still use actions that target Node.js 20. The runner forces them onto Node.js 24 and every run shows a deprecation annotation.

What

This PR updates those actions to their latest major versions, which run on Node.js 24. No workflow inputs change.

Implementation decisions

• Each action keeps a major tag, as before.

  Action	Before	After
  actions/checkout	v4	v7
  actions/setup-java	v4	v6
  actions/configure-pages	v5	v6
  actions/deploy-pages	v4	v5
  actions/stale	v9	v11
  actions/upload-pages-artifact	v3	v5

• actions/upload-pages-artifact is a composite action, but v3 calls actions/upload-artifact@v4, which targets Node.js 20. v5 calls actions/upload-artifact v7.

• None of the breaking changes in the crossed major versions affects how we use these actions:

  • actions/checkout v6 stores credentials in a separate file. No workflow pushes with git.
  • actions/checkout v7 blocks checking out fork PRs in pull_request_target and workflow_run. We use neither trigger.
  • actions/upload-pages-artifact v4 excludes dotfiles. The Javadoc site has none.
  • The inputs of actions/setup-java and actions/stale that we use remain in the new versions.

• actions/setup-java v6 caches the Gradle wrapper separately, so the first run after merge may miss the cache.

How to test

• CI on this PR runs the Gradle build, license and e2e workflows with the new actions.
• After merge, check these workflows, which do not run on this PR:
  • The Javadoc workflow on master deploys to GitHub Pages.
  • The yamory workflow on master runs with the new actions/checkout and actions/setup-java.
  • The scheduled stale workflow runs with actions/stale v11.

Checklist

• Updated documentation if it is required.
• Added/updated tests if it is required. (or tested manually)
• Passed lint and test on the root directory.