Enable partial clone by default

[davidak]

Feature Description

This feature is needed to make Gitea viable for game development and other projects that have a lot of big files.

Currently, only a server admin can enable it manually: https://docs.gitea.io/en-us/clone-filters/

GitHub and Gitlab have it enabled, so i don't think it should cause any issues for us.

We can test it first on try.gitea.io if you have no experience if it causes any bigger issues. From my understanding it should not affect regular clones.

I think this issue was not completely finished: #12170

Screenshots

No response