Support changing labels of Actions runner without re-registration (#24806)

close #24540

related:
- Protocol: https://gitea.com/gitea/actions-proto-def/pulls/9
- Runner side: https://gitea.com/gitea/act_runner/pulls/201

changes:
- Add column of `labels` to table `action_runner`, and combine the value
of `agent_labels` and `custom_labels` column to `labels` column.
- Store `labels` when registering `act_runner`.
- Update `labels` when `act_runner` starting and calling `Declare`.
- Users cannot modify the `custom labels` in edit page any more.

other changes:
- Store `version` when registering `act_runner`.
- If runner is latest version, parse version from `Declare`. But older
version runner still parse version from request header.

templates/shared/actions/runner_list.tmpl

@@ -67,7 +67,7 @@
 						<td>{{if .Version}}{{.Version}}{{else}}{{$.locale.Tr "unknown"}}{{end}}</td>
 						<td><span data-tooltip-content="{{.BelongsToOwnerName}}">{{.BelongsToOwnerType.LocaleString $.locale}}<span></td>
 						<td class="runner-tags">
-							{{range .AllLabels}}<span class="ui label">{{.}}</span>{{end}}
+							{{range .AgentLabels}}<span class="ui label">{{.}}</span>{{end}}
 						</td>
 						<td>{{if .LastOnline}}{{TimeSinceUnix .LastOnline $.locale}}{{else}}{{$.locale.Tr "never"}}{{end}}</td>
 						<td class="runner-ops">