CI: actions/checkout and actions/setup-python targeting deprecated Node.js 20

[dominicci13]

Deprecation warning detected in CI

Every job in the most recent CI run (#27984753086, 2026-06-22) ends with:

##[warning]Node.js 20 is deprecated. The following actions target Node.js 20
but are being forced to run on Node.js 24:
  actions/checkout@v4, actions/setup-python@v5.
For more information see:
  https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

GitHub is already forcing these actions to run under Node.js 24 (CI still passes), but once Node.js 20 support is fully removed from runners the workflow will break.

Affected file

.github/workflows/install.yml:

- uses: actions/checkout@v4
- uses: actions/setup-python@v5

How to fix

Find the first release of each action that declares using: node24 in its action.yml, then update the workflow to that version tag:

- uses: actions/checkout@v5        # or whichever version first uses node24
- uses: actions/setup-python@v6    # or whichever version first uses node24

Check the release pages for the right tags:

• https://github.com/actions/checkout/releases
• https://github.com/actions/setup-python/releases

No other changes are needed — the python -m pip install -e ".[dev]" invocation and the rest of the workflow steps are unaffected.

Priority

Medium — CI is still green (GitHub forces execution on Node 24), but this will become a hard failure once the Node 20 compatibility shim is removed from runners.