[--Dashboard-- data source] AdHoc filtering: Remove feature toggle (#113674)

* Remove dashboardDsAdHocFiltering feature toggle

The dashboardDsAdHocFiltering feature toggle has been enabled by default
and is now in General Availability stage. This commit removes the feature
toggle and makes the AdHoc filtering functionality for the dashboard
datasource permanently available.

Changes:
- Remove feature toggle from registry.go
- Regenerate feature toggle files
- Remove conditional checks in frontend code
- Update tests to reflect permanent enablement
- Always show AdHoc Filters toggle in dashboard query editor
- Always enable dashboard datasource in DataSourcePicker for variables

* Remove unused imports

* Fix Prettier formatting issues

pkg/services/featuremgmt/registry.go

@@ -1942,14 +1942,6 @@ var (
 			HideFromAdminPage: true,
 			HideFromDocs:      true,
 		},
-		{
-			Name:         "dashboardDsAdHocFiltering",
-			Description:  "Enables adhoc filtering support for the dashboard datasource",
-			Stage:        FeatureStageGeneralAvailability,
-			Owner:        grafanaDataProSquad,
-			FrontendOnly: true,
-			Expression:   "true",
-		},
 		{
 			Name:         "dashboardLevelTimeMacros",
 			Description:  "Supports __from and __to macros that always use the dashboard level time range",

pkg/services/featuremgmt/toggles_gen.csv

@@ -250,7 +250,6 @@ foldersAppPlatformAPI,experimental,@grafana/grafana-search-navigate-organise,fal
 otelLogsFormatting,experimental,@grafana/observability-logs,false,false,true
 alertingNotificationHistory,experimental,@grafana/alerting-squad,false,false,false
 unifiedStorageSearchDualReaderEnabled,experimental,@grafana/search-and-storage,false,false,false
-dashboardDsAdHocFiltering,GA,@grafana/datapro,false,false,true
 dashboardLevelTimeMacros,experimental,@grafana/dashboards-squad,false,false,true
 alertmanagerRemoteSecondaryWithRemoteState,experimental,@grafana/alerting-squad,false,false,false
 restrictedPluginApis,experimental,@grafana/plugins-platform-backend,false,false,true

pkg/services/featuremgmt/toggles_gen.go

@@ -1010,10 +1010,6 @@ const (
 	// Enable dual reader for unified storage search
 	FlagUnifiedStorageSearchDualReaderEnabled = "unifiedStorageSearchDualReaderEnabled"
 
-	// FlagDashboardDsAdHocFiltering
-	// Enables adhoc filtering support for the dashboard datasource
-	FlagDashboardDsAdHocFiltering = "dashboardDsAdHocFiltering"
-
 	// FlagDashboardLevelTimeMacros
 	// Supports __from and __to macros that always use the dashboard level time range
 	FlagDashboardLevelTimeMacros = "dashboardLevelTimeMacros"

pkg/services/featuremgmt/toggles_gen.json

@@ -1061,6 +1061,7 @@
         "name": "dashboardDsAdHocFiltering",
         "resourceVersion": "1756814786992",
         "creationTimestamp": "2025-07-23T08:12:25Z",
+        "deletionTimestamp": "2025-09-27T19:59:33Z",
         "annotations": {
           "grafana.app/updatedTimestamp": "2025-09-02 12:06:26.992384 +0000 UTC"
         }