Pre-commit refresh.

- Use .pre-commit-config.yaml Git skeleton, updating some hooks.
- Remove the Python linters, there's no Python code or planned to be.
- Remove the pre-commit manifest validate hook, there are no pre-commit
  hooks.
- Remove the yamltool formatter, it's too broad (I need to do something
  about that).
- Specify the Ansible playbooks for the syntax check hook, actually
  check them instead of skipping with no files found.