Improve CI pipeline build time.

[acelaya]

• Run more jobs in parallel when possible
  • Right now mutation tests don't start until all tests have finished, when every type of mutation tests only depends to its corresponding test type (unit, db, api and cli). Using local reusable workflows could help without duplicating code.
• Setup PHP step is quite slow
  • Caching extensions might help, as openswoole could take time to install.
  • Reduce duplicated code if possible.
• Uploading and downloading artifacts is quite slow.
  • We generate coiverage reports in many formats, but we don't need all of them. Try to upload only the cov and clover coverage, and avoid html one that includes a lot of files.
  • Check if it's possible to download only the corresponding code coverage when running mutation tests.
  • Check if it's possible to download only cov coverages when generating the full coverage to upload to codecov.
• Running mutation tests is slower than other processes.
  • Maybe we should run mutation tests over changed code instead of all code.
  • Check if it's possible to not dump reports, and if that improves performance.