Fix linting errors

src/registrar/models/domain_invitation.py

@@ -3,7 +3,7 @@
 import logging
 
 from django.contrib.auth import get_user_model
-from django.db import models, IntegrityError
+from django.db import models
 
 from django_fsm import FSMField, transition  # type: ignore
 
@@ -63,12 +63,16 @@ class DomainInvitation(TimeStampedModel):
 
         # and create a role for that user on this domain
         try:
-            role = UserDomainRole.objects.get(
+            UserDomainRole.objects.get(
                 user=user, domain=self.domain, role=UserDomainRole.Roles.ADMIN
             )
         except UserDomainRole.DoesNotExist:
-            UserDomainRole.objects.create(user=user, domain=self.domain, role=UserDomainRole.Roles.ADMIN)
+            UserDomainRole.objects.create(
+                user=user, domain=self.domain, role=UserDomainRole.Roles.ADMIN
+            )
         else:
             # something strange happened and this role already existed when
             # the invitation was retrieved. Log that this occurred.
-            logger.warn("Invitation %s was retrieved for a role that already exists.", self)
+            logger.warn(
+                "Invitation %s was retrieved for a role that already exists.", self
+            )

src/registrar/models/user.py

@@ -55,4 +55,6 @@ class User(AbstractUser):
                 # retrieving should not fail because of a missing user, but
                 # if it does fail, log the error so a new user can continue
                 # logging in
-                logger.warn("Failed to retrieve invitation %s", invitation,  exc_info=True)
+                logger.warn(
+                    "Failed to retrieve invitation %s", invitation, exc_info=True
+                )

src/registrar/tests/test_models.py

@@ -192,7 +192,9 @@ class TestInvitations(TestCase):
 
     def test_retrieve_existing_role_no_error(self):
         # make the overlapping role
-        UserDomainRole.objects.get_or_create(user=self.user, domain=self.domain, role=UserDomainRole.Roles.ADMIN)
+        UserDomainRole.objects.get_or_create(
+            user=self.user, domain=self.domain, role=UserDomainRole.Roles.ADMIN
+        )
         # this is not an error but does produce a console warning
         with less_console_noise():
             self.invitation.retrieve()