use css on labels (#25626) (#25636)

Backport #25626 by @derelm

Changes html to use CSS label class similar to
`templates/shared/actions/runner_list.tmpl`

Before:

![grafik](https://github.com/go-gitea/gitea/assets/465155/6729d580-3ea6-4a90-972e-6e5117459da7)

After:

![grafik](https://github.com/go-gitea/gitea/assets/465155/d4fc280c-c40b-4db4-b1ba-877270f875c8)


List view (for reference - unchanged):

![grafik](https://github.com/go-gitea/gitea/assets/465155/5ad2d8d1-2fb5-414d-823b-48a368a74724)

Co-authored-by: derelm <[email protected]>

Author: GiteaBot

templates/shared/actions/runner_edit.tmpl

@@ -19,7 +19,7 @@
 					<label>{{.locale.Tr "actions.runners.agent_labels"}}</label>
 					<span>
 						{{range .Runner.AgentLabels}}
-						<span>{{.}}</span>
+						<span class="ui label">{{.}}</span>
 						{{end}}
 					</span>
 				</div>