Update actions/cache from v2.1.7 to v3

[RytoEX]

Description

Update actions/cache from v2.1.7 to v3.

Motivation and Context

Want to have up-to-date actions and make it easier for plugin maintainers to do the same. We consider it acceptable to update first-party GitHub Actions to v3 instead of pinning to a specific release.

How Has This Been Tested?

The CI run will have to suffice. We've updated to v3 for all first-party actions everywhere else, so I have no reason to believe this will be a problem here.

Types of changes

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

Checklist:

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