use css on labels (go-gitea#25626)

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

Author: derelm

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>