Update github actions to fix deprecation warnings

[acrespo]

Warnings abou node 16 deprecation and moving to node20. Also, upload artifact ation needs updating to v4, with some warning about breaking changes.

See:

• https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/
• https://github.blog/changelog/2024-04-16-deprecation-notice-v3-of-the-artifact-actions/
  • breaking changes; https://github.com/actions/upload-artifact?tab=readme-ov-file#breaking-changes

see: https://github.com/muun/apollo/actions/runs/8942644617