Updates to correct a11y issues with CodeMirror

TNL-5281

common/lib/capa/capa/templates/codeinput.html

@@ -5,7 +5,9 @@ from openedx.core.djangolib.markup import HTML
 %>
 <div id="textbox_${id}" class="capa_inputtype textbox cminput">
   % if response_data['label']:
-      <label class="problem-group-label" for="cm-textarea-${id}">${response_data['label']}</label>
+    <label class="problem-group-label" for="cm-textarea-${id}">${response_data['label']}</label>
+  % else:
+    <label class="sr problem-group-label" for="cm-textarea-${id}">${_('Code Editor')}</label>
   % endif
   <textarea rows="${rows}" cols="${cols}" name="input_${id}"
             aria-label="${aria_label}"

common/test/acceptance/tests/studio/test_studio_settings.py

@@ -502,15 +502,6 @@ class StudioSettingsA11yTest(StudioCourseTest):
             ],
         })
 
-        # TODO: Figure out how to get CodeMirror to pass accessibility testing
-        # We use the CodeMirror Javascript library to
-        # add code editing to a number of textarea elements
-        # on this page. CodeMirror generates markup that does
-        # not pass our accessibility testing rules.
-        self.settings_page.a11y_audit.config.set_scope(
-            exclude=['.CodeMirror textarea']  # TODO: TNL-5831
-        )
-
         self.settings_page.a11y_audit.check_for_accessibility_errors()