ci: update GitHub Actions to Node 24 majors

[mrrobot47]

Summary

GitHub Actions runners now force actions built for Node 20 onto Node 24 and print a deprecation warning on every run (e.g. "Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v3, actions/checkout@v3, actions/upload-artifact@v4"). Once Node 20 is removed from runners these steps will fail. This bumps every action in test_and_build.yml to its latest major that declares runs.using: node24.

Changes

Action	Before	After
actions/checkout	v3	v7
actions/cache	v3	v6
actions/upload-artifact	v4	v7
actions/download-artifact	v4	v8
softprops/action-gh-release	v1	v3
ad-m/github-push-action	master	v1.3.0 (pinned)
shivammathur/setup-php	v2	unchanged (already node24)

Compatibility notes

• upload-artifact v7 and download-artifact v8 use the same artifact backend, so the phar and VERSION artifacts passed between jobs keep working. Direct (unzipped) uploads are opt-in and not used here. download-artifact v8 now fails on a digest mismatch instead of warning.
• checkout v6+ persists credentials to a separate file; the easyengine-builds checkout and push both pass their own token, so the deploy job is unaffected. checkout v7 blocks fork PR checkouts only for pull_request_target/workflow_run, which this workflow doesn't use.
• action-gh-release v3 keeps the inputs used here (body_path, files, draft, name, token).
• Pinning github-push-action to a release makes the deploy step reproducible instead of tracking master.

Testing

• actionlint: the "action is too old to run" errors for checkout@v3, cache@v3 and action-gh-release@v1 are gone; the remaining findings are pre-existing shellcheck notes in run: scripts.
• The build and Behat jobs run on this PR. The deploy and release jobs only run on develop pushes and tags, so they'll be exercised by the next nightly and release.