Refactor DateUtils and merge TimeSince (#32409)

Follow #32383 and #32402

templates/shared/actions/runner_list.tmpl

@@ -73,7 +73,7 @@
 						<td class="tw-flex tw-flex-wrap tw-gap-2 runner-tags">
 							{{range .AgentLabels}}<span class="ui label">{{.}}</span>{{end}}
 						</td>
-						<td>{{if .LastOnline}}{{TimeSinceUnix .LastOnline ctx.Locale}}{{else}}{{ctx.Locale.Tr "never"}}{{end}}</td>
+						<td>{{if .LastOnline}}{{DateUtils.TimeSince .LastOnline}}{{else}}{{ctx.Locale.Tr "never"}}{{end}}</td>
 						<td class="runner-ops">
 							{{if .Editable $.RunnerOwnerID $.RunnerRepoID}}
 							<a href="{{$.Link}}/{{.ID}}">{{svg "octicon-pencil"}}</a>