Fix GH Action test: data-bs-dismiss modal close

`execute_script('arguments[0].click();', modal_close_button)` works locally, however, the modal seems to be failing to close when the test is run as a GitHub Action.
  -  Strangely `execute_script('arguments[0].click();', modal_close_button)` works as a GitHub Action when executed for the 'Modal search opens and closes and allows user to search, select and remove items' test within this same file.

spec/features/modal_search_spec.rb

@@ -61,8 +61,8 @@
       fill_in 'research_output_search_term', with: @model.name
       click_button 'Apply filter(s)'
       click_link 'Select'
-      modal_close_button = find('.modal-header button.btn-close')
-      execute_script('arguments[0].click();', modal_close_button)
+      # (execute_script('arguments[0].click();', modal_close_button) works locally here, but not as GitHub Action)
+      find('[data-bs-dismiss="modal"]').click
     end
 
     click_button 'Save'