Remove obsolete CSS text classes (#30576)

- `.text-thin` and `.text-italic` are not present in CSS so were doing nothing and I removed them.
- `.text.middle` was unused so I removed it.
- `.text.italic` is replaced with `tw-italic`.
- `.text.normal` had exactly one use and it wasn't even needed.
- add a `muted` class to the link to `org_profile_avatar.tmpl`.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
(cherry picked from commit aff7b7bdd285cc1fcabea774f153886e11ae9f5d)

templates/org/team/members.tmpl

@@ -46,7 +46,7 @@
 							</div>
 						{{else}}
 							<div class="flex-item">
-								<span class="text grey italic">{{ctx.Locale.Tr "org.teams.members.none"}}</span>
+								<span class="text grey tw-italic">{{ctx.Locale.Tr "org.teams.members.none"}}</span>
 							</div>
 						{{end}}
 					</div>

templates/org/team/repositories.tmpl

@@ -48,7 +48,7 @@
 							</div>
 						{{else}}
 							<div class="flex-item">
-								<span class="text grey italic">{{ctx.Locale.Tr "org.teams.repos.none"}}</span>
+								<span class="text grey tw-italic">{{ctx.Locale.Tr "org.teams.repos.none"}}</span>
 							</div>
 						{{end}}
 					</div>

templates/org/team/sidebar.tmpl

@@ -22,7 +22,7 @@
 			{{if .Team.Description}}
 				{{.Team.Description}}
 			{{else}}
-				<span class="text grey italic">{{ctx.Locale.Tr "org.teams.no_desc"}}</span>
+				<span class="text grey tw-italic">{{ctx.Locale.Tr "org.teams.no_desc"}}</span>
 			{{end}}
 		</div>
 		{{if eq .Team.LowerName "owners"}}