Build: reset notifications when reseting a build (#11027)

* Build: reset notifications when reseting a build

When the build is retried for any reason we call `build.reset()` to make sure
the build is fresh. I'm adding the removal of all the notifications that were
attached to the build when reseting it.

* Add missing imports

readthedocs/builds/models.py

@@ -1119,6 +1119,7 @@ def reset(self):
         self.builder = ''
         self.cold_storage = False
         self.commands.all().delete()
+        self.notifications.all().delete()
         self.save()
 
 

readthedocs/rtd_tests/tests/test_api.py

@@ -49,7 +49,9 @@
     LATEST,
 )
 from readthedocs.builds.models import APIVersion, Build, BuildCommandResult, Version
+from readthedocs.doc_builder.exceptions import BuildUserError
 from readthedocs.integrations.models import GenericAPIWebhook, Integration
+from readthedocs.notifications.models import Notification
 from readthedocs.oauth.models import (
     RemoteOrganization,
     RemoteOrganizationRelation,
@@ -108,7 +110,13 @@ def test_reset_build(self):
         )
         build.commands.add(command)
 
+        Notification.objects.add(
+            attached_to=build,
+            message_id=BuildUserError.SKIPPED_EXIT_CODE_183,
+        )
+
         self.assertEqual(build.commands.count(), 1)
+        self.assertEqual(build.notifications.count(), 1)
 
         client = APIClient()
         _, build_api_key = BuildAPIKey.objects.create_key(self.project)
@@ -129,6 +137,7 @@ def test_reset_build(self):
         self.assertEqual(build.builder, '')
         self.assertFalse(build.cold_storage)
         self.assertEqual(build.commands.count(), 0)
+        self.assertEqual(build.notifications.count(), 0)
 
 
     def test_api_does_not_have_private_config_key_superuser(self):