Make GHA cache restore any cache from current month if dependencies do not match

[carbolymer]

Changelog

- description: |
    Make GHA cache restore any cache from current month if dependencies do not match
# uncomment types applicable to the change:
  type:
  # - feature        # introduces a new feature
  # - breaking       # the API has changed in a breaking way
  # - compatible     # the API has changed but is non-breaking
  # - optimisation   # measurable performance improvements
  # - improvement    # QoL changes e.g. refactoring
  # - bugfix         # fixes a defect
  # - test           # fixes/modifies tests
   - maintenance    # not directly related to the code
  # - release        # related to a new release preparation
  # - documentation  # change in code docs, haddocks...

Context

Make GHA cache restore any cache from current month if dependencies do not match.

Checklist

• Commit sequence broadly makes sense and commits have useful messages
• New tests are added if needed and existing tests are updated. See Running tests for more details
• Self-reviewed the diff

[carbolymer]

I'm not sure about having dist-newstyle here now. I feel it may produce build errors due to accumulating builds' outputs. Or it may not. I'd leave it here for now, and remove if it starts giving us issues.

[smelc]

I think it should be fine.

[smelc]

LGTM 👍

[Jimbo4350]

I think we can increase how long we hold on to caches for a in the repo settings.

[carbolymer]

I don't see this option. Artifacts and logs retention time can be configured, but I don't think caches can.