Tempo: If no search tag then do not query API for tag values (#72522)

* If no tag then do not query api for tag values

* Update test

public/app/plugins/datasource/tempo/SearchTraceQLEditor/SearchField.test.tsx

@@ -128,7 +128,7 @@ describe('SearchField', () => {
     };
     const { container } = renderSearchField(updateFilter, filter, ['tag1', 'tag22', 'tag33']);
 
-    const select = await container.querySelector(`input[aria-label="select test1 tag"]`);
+    const select = container.querySelector(`input[aria-label="select test1 tag"]`);
     expect(select).not.toBeNull();
     expect(select).toBeInTheDocument();
     if (select) {

public/app/plugins/datasource/tempo/SearchTraceQLEditor/SearchField.tsx

@@ -60,7 +60,7 @@ const SearchField = ({
 
   const updateOptions = async () => {
     try {
-      return await languageProvider.getOptionsV2(scopedTag);
+      return filter.tag ? await languageProvider.getOptionsV2(scopedTag) : [];
     } catch (error) {
       // Display message if Tempo is connected but search 404's
       if (isFetchError(error) && error?.status === 404) {