github actions - actions/cache scheduled for deprecation

[emteknetnz]

The following annotation shows in CI runs:

Your workflow is using a version of actions/cache that is scheduled for deprecation, actions/cache@3624ceb. Please update your workflow to use either v3 or v4 of actions/cache to avoid interruptions. Learn more: https://github.blog/changelog/2024-12-05-notice-of-upcoming-releases-and-breaking-changes-for-github-actions/#actions-cache-v1-v2-and-actions-toolkit-cache-package-closing-down

Acceptance criteria

• The version of actions/cache is updated
• The annotation no longer shows

[GuySartorelli]

Where is this showing? We updated most of them as part of #316

[emteknetnz]

A regular CI build? https://github.com/silverstripe/silverstripe-framework/actions/runs/12784567720 is one example