ci: update caching to resolve concurrency

[Borda]

What does this PR do?

we have some false negative CI failing on master when multiple jobs try to update caches simultaneously. It also blocks the jobs for a much longer time than required...

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

Did you have fun?

Make sure you had fun coding 🙃

---

📚 Documentation preview 📚: https://torchmetrics--2869.org.readthedocs.build/en/2869/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 41%. Comparing base (d9697b6) to head (14ac882).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #2869     +/-   ##
========================================
- Coverage      69%     41%    -28%     
========================================
  Files         346     346             
  Lines       19142   19142             
========================================
- Hits        13230    7891   -5339     
- Misses       5912   11251   +5339