pwa: delete pwa push subscription on 410 errors (#41304)

combo/apps/pwa/signals.py

@@ -59,5 +59,8 @@ def notification(sender, instance=None, created=False, **kwargs):
                     vapid_claims=claims,
                     )
         except pywebpush.WebPushException as e:
+            if str(e) == 'Push failed: 410 Gone':
+                subscription.delete()
+                continue
             logger = logging.getLogger(__name__)
             logger.exception('webpush error (%r)', e)