Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* Exclude vendor dirs from git CRLF normalization

Should get rid of a few warnings like at the end of `lint-backend` like
https://drone.gitea.io/go-gitea/gitea/23117/1/4

* make vendor

Co-authored-by: John Olheiser <john.olheiser@gmail.com>
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

This will ensure our repo is always checked out with LF line endings
which should help Windows users who have line ending normalization
enabled.

Additionally, added the LF preference to .editorconfig.