Fix duplicate role name when aria-roledescription is present

When an element has aria-roledescription (e.g. Discord messages use
'Message'), _generateRoleName was adding both the roledescription AND
the standard localized role name (e.g. 'article'). This resulted in
the role being announced twice.

The aria-roledescription attribute is intended to replace the standard
role name, not supplement it. Return early after adding the
roledescription to match Orca's behavior.

src/cthulhu/scripts/web/speech_generator.py

@@ -560,6 +560,9 @@ class SpeechGenerator(speech_generator.SpeechGenerator):
         if roledescription:
             result = [roledescription]
             result.extend(self.voice(speech_generator.SYSTEM, obj=obj, **args))
+            # aria-roledescription replaces the standard role name, so return
+            # early to avoid announcing both (e.g. "Message" + "article").
+            return result
 
         role = args.get('role', AXObject.get_role(obj))
         roleSoundPresentation = cthulhu.cthulhuApp.settingsManager.getSetting('roleSoundPresentation')