DatasourceRef: keep uid/type ref when using template variables (#41785)

public/app/features/query/state/PanelQueryRunner.test.ts

@@ -114,6 +114,7 @@ function describeQueryRunnerScenario(
           ctx.queryCalledWith = options;
           return Promise.resolve(response);
         },
+        getRef: () => ({ type: 'test', uid: 'TestDB-uid' }),
         testDatasource: jest.fn(),
       };
 

public/app/features/query/state/PanelQueryRunner.ts

@@ -235,7 +235,7 @@ export class PanelQueryRunner {
       // Attach the data source name to each query
       request.targets = request.targets.map((query) => {
         if (!query.datasource) {
-          query.datasource = { uid: ds.uid };
+          query.datasource = ds.getRef();
         }
         return query;
       });