Don't include link of deleted branch when listing branches (#31028) (#31032)

Don't include link of deleted branch when listing branches (#31028) (#31032)

Backport #31028 by @kemzeb

From
https://github.com/go-gitea/gitea/issues/31018#issuecomment-2119622680.

This commit removes the link to a deleted branch name because it returns
a 404 while it is in this deleted state. GitHub also throws a 404 when
navigating to a branch link that was just deleted, but this deleted
branch is removed from the branch list after a page refresh. Since with
Gitea this deleted branch would be kept around for quite some time
(well, until the "cleanup deleted branches" cron job begins), it makes
sense to not have this as a link that users can navigate to.

Co-authored-by: Kemal Zebari <60799661+kemzeb@users.noreply.github.com>