[Discover-Next] conditionally render selector

When selecting a specific language, the data source selector disappears and relies completely on the
query editor when enhancements are enabled.

If toggled on and then off, everything is working properly.

opensearch-project#7046

Signed-off-by: Kawika Avilla <kavilla414@gmail.com>

src/plugins/data/public/ui/query_editor/query_editor.tsx

@@ -311,6 +311,7 @@ export default class QueryEditorUI extends Component<Props, State> {
                 scrollBeyondLastLine: false,
                 wordWrap: 'on',
                 wrappingIndent: 'indent',
+                selectionHighlight: false,
               }}
             />
           </EuiFlexItem>