build: add generated files lists/patterns to .gitattributes

[rmuir]

This is a nice easy win on the PR review, since generated files are folded away and clearly marked in the UI.

Some patterns were used to try to keep this low-maintenance, but I tried to not make the patterns too aggressive that they'd bring in false positives.

Closes #14833

[uschindler]

Why is this called "linguist-generated"? No worries, I am just interested!

[rmuir]

@uschindler more details here: https://docs.github.com/en/repositories/working-with-files/managing-files/customizing-how-changed-files-appear-on-github

relates to https://github.com/github-linguist/linguist

[dweiss]

Didn't know about such a thing. Interesting.

[uschindler]

It would be cool if all regenerate tasks make sure the file is listed there. Basically all files listed with json hash should appear here.
Maybe think about that as separate issue.

[rmuir]

It would be cool if all regenerate tasks make sure the file is listed there. Basically all files listed with json hash should appear here.
Maybe think about that as separate issue.

Could be done with git check-attr linguist-generated <file> maybe. i dont want to mess with that here.

The way in which this is used by the github UI... it is not critical that the attributes are perfect.

Github even does a bunch of assumptions and guesswork already today: you can use -linguist-generated syntax to disable their guesswork in cases where they are wrong.

Try not to think of this feature like a German. :)

[rmuir]

also, IMO an easy solution to managing the generated files, is to always put them in a subdirectory named generated.

Then you can use glob such as **/generated/** in this file, github actions include/exclude, prek include/exclude, etc.

It also stands out MUCH better as file is very clearly indicated as generated by having the word in its path.