File Tree Diff: allow users to ignore files (#11977)
Add a field to allow users to tell us what files should be ignored when
comparing versions. This is going to be used by the front-end to don't
expose these files in the list of added/modified/deleted files.
[Peek 2025-02-05
14-26.webm](https://github.com/user-attachments/assets/f6e45326-fead-4f40-8b76-36a82b1d6cb0)
Closes https://github.com/readthedocs/readthedocs.org/issues/11694
