Refactor pre-submit test workflows

[ggiguash]

As we are adding more pre-submit tests, we should agree on a maintainable structure.

The proposal is to split the current presubmit.yaml into the following parts:

• linters/
  • Static code checkers.
  • This is where hadolint and shellcheck would end up
• builders/
  • Build and deploy from sources.
  • This is where centos9-bootc, centos10-bootc, fedora-bootc and isolated tests would end up
• installers/
  • Deploy pre-built images coming from package repositories.
  • This is where quick-start-and-clean test would end up.
• testers/
  • Workloads and/or scripts performing checks on a running system.