Replace actionlint-docker pre-commit hook

[seifertm]

The actionlint-docker pre-commit hook requires users to have a working Docker setup, in order to make changes to pytest-asyncio.

1. This prevents the linting from running as part of the CI.
2. I don't think it's reasonable to require Docker in pre-commit hooks. If we want to have more contributors to the pytest-asyncio, the project setup should be as easy as possible.

However, I do believe that linting of GitHub actions files is a good thing to have. I suggest to find a dockerless alternative for the existing actionlint-docker hook. This would simplify the dev setup and enable GitHub action linting in the CI.

If there's no alternative available (not even yaml linting), I think that a complete removal of actionlint-docker should be considered.