Remove axe exceptions for unused typeahead and bootstrap 4

spec/features/axe_spec.rb

@@ -3,36 +3,31 @@
 RSpec.describe 'Accessibility testing', :js, api: false do
   it 'validates the home page' do
     visit root_path
-    expect(page).to be_accessible
+    expect(page).to be_axe_clean
   end
 
   it 'validates the catalog page' do
     visit root_path
     fill_in "q", with: 'history'
     click_on 'search'
 
-    expect(page).to be_accessible
+    expect(page).to be_axe_clean
 
     within '.accordion-item.blacklight-language_ssim' do
       click_on 'Language'
       click_on "Tibetan"
     end
 
-    expect(page).to be_accessible
+    expect(page).to be_axe_clean
   end
 
   it 'validates the advanced search form' do
     visit advanced_search_catalog_path
-    expect(page).to be_accessible
+    expect(page).to be_axe_clean
   end
 
   it 'validates the single results page' do
     visit solr_document_path('2007020969')
-    expect(page).to be_accessible
-  end
-
-  def be_accessible(skipping: [])
-    # typeahead does funny things with the search bar
-    be_axe_clean.excluding('.tt-hint').skipping(skipping + [('color-contrast' if defined?(Bootstrap) && Bootstrap::VERSION < '5')].compact)
+    expect(page).to be_axe_clean
   end
 end