Show also tags without release in releases sub-tab

[lafriks]

Currently it is very confusing that tags that has no associated release does not show in Releases sub-tab of Releases tab.

Previous versions of Gitea did show them and also GitHub does it same way.

[lunny]

You can find them in Code -> Tags

[noerw]

Hm, github has a very unclear distinction between tags and releases, which has benefits and drawbacks, so just following gh here is not by default great..
Seing a chronologically sorted list of all tags+releases is a useful feature to check on updates to a project, so I'd agree to revert this change

For reference, this was introduced + discussed in #12096 (comment)