Fix GH Action test: close modal via Bootstrap API

- Manual button click simulation for closing the modal works locally but fails in GitHub Actions. Switching to Bootstrap's modal('hide') API call provides reliable modal closing behavior across all environments.
  - Strangely, `execute_script('arguments[0].click();', modal_close_button)` works for the  'Modal search opens and closes and allows user to search, select and remove items' test within this same file.

Author: aaronskiba

spec/features/modal_search_spec.rb

@@ -61,8 +61,9 @@
       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)
+      # Bootstrap's modal API is necessary for modal to close when test is run as GitHub Action
+      # (execute_script('arguments[0].click();', modal_close_button) somehow works for the other test within this file)
+      execute_script("$('#modal-search-repositories').modal('hide')")
     end
 
     click_button 'Save'