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.

routers/api/actions/runner/interceptor.go

@@ -21,11 +21,10 @@ import (
 )
 
 const (
-	uuidHeaderKey    = "x-runner-uuid"
-	tokenHeaderKey   = "x-runner-token"
+	uuidHeaderKey  = "x-runner-uuid"
+	tokenHeaderKey = "x-runner-token"
+	// Deprecated: will be removed after Gitea 1.20 released.
 	versionHeaderKey = "x-runner-version"
-
-	versionUnknown = "Unknown"
 )
 
 var withRunner = connect.WithInterceptors(connect.UnaryInterceptorFunc(func(unaryFunc connect.UnaryFunc) connect.UnaryFunc {
@@ -36,11 +35,9 @@ var withRunner = connect.WithInterceptors(connect.UnaryInterceptorFunc(func(unar
 		}
 		uuid := request.Header().Get(uuidHeaderKey)
 		token := request.Header().Get(tokenHeaderKey)
+		// TODO: version will be removed from request header after Gitea 1.20 released.
+		// And Gitea will not try to read version from reuqest header
 		version := request.Header().Get(versionHeaderKey)
-		if util.IsEmptyString(version) {
-			version = versionUnknown
-		}
-		version, _ = util.SplitStringAtByteN(version, 64)
 
 		runner, err := actions_model.GetRunnerByUUID(ctx, uuid)
 		if err != nil {
@@ -54,7 +51,11 @@ var withRunner = connect.WithInterceptors(connect.UnaryInterceptorFunc(func(unar
 		}
 
 		cols := []string{"last_online"}
-		if runner.Version != version {
+
+		// TODO: version will be removed from request header after Gitea 1.20 released.
+		// And Gitea will not try to read version from reuqest header
+		version, _ = util.SplitStringAtByteN(version, 64)
+		if !util.IsEmptyString(version) && runner.Version != version {
 			runner.Version = version
 			cols = append(cols, "version")
 		}