Include `.pyw` files by default

[charliermarsh]

Random but I was looking back at #3914 and now that I have more familiarity from my time in uv, I think .pyw should just be included by default? They're Python files, just intended to run with a GUI etc.

[iamlucasvieira]

I'm new here, do you think this is something I could pick up?

[MichaReiser]

I'm new here, do you think this is something I could pick up?

Possibly. It is a breaking change. That means we can't just merge the PR but must wait for the next minor. We should probably make this a preview change first. Although we may even decide to only ship the preview change as part of the next minor release.

One thing we have to be careful about is that we only include pyw when discovering python files to lint. I don't think we should include pyw files when, e.g., discovering packages.