Dashboards: Remove advancedDataSourcePicker feature toggle (#81790)

* remove advancedDataSourcePicker feature toggle from DataSourcePickerWithPrompt

* remove advancedDataSourcePicker toggle from DataSourcePicker and adjust tests that relied on old picker

* adjust failing tests in QueryVariableEditorForm

* move DataSourceDropdown to DataSourcePicker file

* covert style declaration syntax to object style in DataSourcePicker

* remove advancedDataSourcePicker  feature flag from registry

* remove .only from test

* adjust QueryVariableEditor test to avoid console.error

public/app/features/query/components/QueryEditorRowHeader.test.tsx

@@ -1,7 +1,6 @@
 import { render, screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import React from 'react';
-import { openMenu } from 'react-select-event';
 
 import { DataSourceInstanceSettings } from '@grafana/data';
 import { selectors } from '@grafana/e2e-selectors';
@@ -84,7 +83,7 @@ describe('QueryEditorRowHeader', () => {
     renderScenario({ onChangeDataSource: () => {} });
 
     const dsSelect = screen.getByTestId(selectors.components.DataSourcePicker.container).querySelector('input')!;
-    openMenu(dsSelect);
+    userEvent.click(dsSelect);
     expect(await screen.findByText('${dsVariable}')).toBeInTheDocument();
   });
 });

public/app/features/query/components/QueryGroup.tsx

@@ -497,7 +497,7 @@ function DataSourcePickerWithPrompt({ options, onChange, ...otherProps }: DataSo
 
   return (
     <>
-      {isDataSourceModalOpen && config.featureToggles.advancedDataSourcePicker && (
+      {isDataSourceModalOpen && (
         <DataSourceModal {...commonProps} onDismiss={() => setIsDataSourceModalOpen(false)}></DataSourceModal>
       )}