[Port] gitea#30033: Remove fomantic header module

Likely still a few useless classes left, but I think I at least don't
have missed any.

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: Giteabot <teabot@gitea.io>

---

Conflict resolution: Trivial
Ref: https://codeberg.org/forgejo/forgejo/issues/2776
(cherry picked from commit f22fe4e1944d8084dec7c04f064a8e782fca94d4)

templates/shared/search/code/results.tmpl

@@ -12,7 +12,7 @@
 	{{range $result := .SearchResults}}
 		{{$repo := or $.Repo (index $.RepoMaps .RepoID)}}
 		<div class="diff-file-box diff-box file-content non-diff-file-content repo-search-result">
-			<h4 class="ui top attached normal header tw-flex tw-flex-wrap">
+			<h4 class="ui top attached header tw-font-normal tw-flex tw-flex-wrap">
 				{{if not $.Repo}}
 					<span class="file tw-flex-1">
 						<a rel="nofollow" href="{{$repo.Link}}">{{$repo.FullName}}</a>