Alerting: Remove alertingSimplifiedRouting feature toggle (#104980)

Co-authored-by: Gilles De Mey <gilles.de.mey@gmail.com>

pkg/services/ngalert/api/api_alertmanager_test.go

@@ -610,7 +610,7 @@ func createMultiOrgAlertmanager(t *testing.T, configs map[int64]*ngmodels.AlertC
 		ngfakes.NewFakeReceiverPermissionsService(),
 		log.New("testlogger"),
 		secretsService,
-		featuremgmt.WithManager(featuremgmt.FlagAlertingSimplifiedRouting),
+		featuremgmt.WithManager(),
 	)
 	require.NoError(t, err)
 	err = mam.LoadAndSyncAlertmanagersForOrgs(context.Background())

pkg/services/ngalert/api/api_ruler.go

@@ -582,7 +582,7 @@ func (srv RulerSrv) updateAlertRulesInGroup(c *contextmodel.ReqContext, groupKey
 		return ErrResp(http.StatusInternalServerError, err, "failed to update rule group")
 	}
 
-	if srv.featureManager.IsEnabled(c.Req.Context(), featuremgmt.FlagAlertingSimplifiedRouting) && dbConfig != nil {
+	if dbConfig != nil {
 		// This isn't strictly necessary since the alertmanager config is periodically synced.
 		err := srv.amRefresher.ApplyConfig(c.Req.Context(), groupKey.OrgID, dbConfig)
 		if err != nil {