CI: Update first-party GitHub Actions from v2 to v4

[RytoEX]

Description

CI: Update first-party GitHub Actions from v2 to v4

GitHub Actions has deprecated Actions based on node16. The v4 actions are based on node20. Replace first-party v2 actions with their v4 counterparts.

See:
https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

Motivation and Context

Want to resolve deprecation warnings on CI. Want to avoid CI failing when the node16 actions are disabled.

How Has This Been Tested?

obs-plugintemplate and obs-deps have had successful CI runs. This repo will test its own CI.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.