Actions are no longer experimental, so enable them by default (#27054)

This PR makes the actions enabled by default, so people will find it
easier to enable actions in repository setting.

modules/setting/actions.go

@@ -19,7 +19,7 @@ var (
 		Enabled               bool
 		DefaultActionsURL     defaultActionsURL `ini:"DEFAULT_ACTIONS_URL"`
 	}{
-		Enabled:           false,
+		Enabled:           true,
 		DefaultActionsURL: defaultActionsURLGitHub,
 	}
 )