Docs: remove outdated note about caching only valid files (fixes #10739)

[ajafff]

What is the purpose of this pull request? (put an "X" next to item)

[x] Documentation update
[ ] Bug fix (template)
[ ] New rule (template)
[ ] Changes an existing rule (template)
[ ] Add autofixing to a rule
[ ] Add a CLI option
[ ] Add something to the core
[ ] Other, please explain:

What changes did you make? (Give an overview)
Remove outdated paragraph.

Is there anything you'd like reviewers to focus on?

[platinumazure]

I think this is probably okay as is, but I'll note that if a file is autofixed, it will not be stored in the cache (or rather, the changing of the file as part of autofix will invalidate the cache entry). So it would need to be linted one more time, and then it would be in the cache.

That said-- not sure that is an important note, so this is probably fine as it is.

[kaicataldo]

I'm all for more documentation in this case so that it's easy to understand what it does both for users and for future maintainers (us!).

[platinumazure]

I think we can just change the note to say that files that are autofixed are not put in the cache (the implication being, everything else will be put in the cache).

What do you think?

[kaicataldo]

@ajafff Friendly ping!

[platinumazure]

@ajafff Friendly ping: Are you able to finish this? Let us know if we can help!

[zacnomore]

I'd like to take this over if that's alright. It's been a number of weeks at this point.

[zacnomore]

Added PR: #10913

[platinumazure]

Closing as #10913 was merged to resolve the original issue. Thanks for contributing regardless, we really appreciate it!