[feature-request] Allow --watch to automatically fix when combined with --fix

[phillipuniverse]

Running the following:

ruff . --fix --watch

I would expect that Ruff would automatically fix files that it watches, not just display the errors. But it appears that the --watch clobbers --fix in that it will watch files and just report the errors.

If I stop watching and then ruff . --fix, ruff automatically fixes issues that it found.

[charliermarsh]

I initially held off on this because --watch is based on file-watching, and autofixing will modify those files thus triggering another invocation. It may actually work as-is, though. I can at least test it out.