migrations: Add migration to revoke invites from old deactivated users.

This is a natural follow-up to
93e8740218 - invitations sent by users
deactivated before the commit still need to be revoked, via a
migration.

The logic for finding the Confirmations to deactivated is based on
get_valid_invite_confirmations_generated_by_user in actions.py.

zerver/migrations/0383_revoke_invitations_from_deactivated_users.py

@@ -0,0 +1,78 @@
+from typing import List
+
+from django.db import migrations
+from django.db.backends.postgresql.schema import DatabaseSchemaEditor
+from django.db.migrations.state import StateApps
+from django.utils.timezone import now as timezone_now
+
+
+def revoke_invitations(apps: StateApps, schema_editor: DatabaseSchemaEditor) -> None:
+    Realm = apps.get_model("zerver", "Realm")
+    Confirmation = apps.get_model("confirmation", "Confirmation")
+    Confirmation.INVITATION = 2
+    Confirmation.MULTIUSE_INVITE = 6
+    PreregistrationUser = apps.get_model("zerver", "PreregistrationUser")
+    UserProfile = apps.get_model("zerver", "UserProfile")
+    MultiuseInvite = apps.get_model("zerver", "MultiuseInvite")
+
+    STATUS_REVOKED = 2
+
+    def get_valid_invite_confirmations_generated_by_users(
+        user_ids: List[int],
+    ) -> List[int]:
+        prereg_user_ids = (
+            PreregistrationUser.objects.filter(referred_by_id__in=user_ids)
+            .exclude(status=STATUS_REVOKED)
+            .values_list("id", flat=True)
+        )
+        confirmation_ids = list(
+            Confirmation.objects.filter(
+                type=Confirmation.INVITATION,
+                object_id__in=prereg_user_ids,
+                expiry_date__gte=timezone_now(),
+            ).values_list("id", flat=True)
+        )
+
+        multiuse_invite_ids = MultiuseInvite.objects.filter(
+            referred_by_id__in=user_ids
+        ).values_list("id", flat=True)
+        confirmation_ids += list(
+            Confirmation.objects.filter(
+                type=Confirmation.MULTIUSE_INVITE,
+                expiry_date__gte=timezone_now(),
+                object_id__in=multiuse_invite_ids,
+            ).values_list("id", flat=True)
+        )
+
+        return confirmation_ids
+
+    print("")
+    for realm_id in Realm.objects.values_list("id", flat=True):
+        deactivated_user_ids = UserProfile.objects.filter(
+            is_active=False, realm_id=realm_id
+        ).values_list("id", flat=True)
+        confirmation_ids = get_valid_invite_confirmations_generated_by_users(deactivated_user_ids)
+        print(f"Revoking Confirmations for realm {realm_id}: {confirmation_ids}")
+        Confirmation.objects.filter(id__in=confirmation_ids).update(expiry_date=timezone_now())
+
+
+class Migration(migrations.Migration):
+    """
+    User deactivation used to *not* revoke invitations generated by the user.
+    This has been fixed in the implementation, but this migration is still needed
+    to ensure old invitations are revoked for users who were deactivated in the past.
+    """
+
+    atomic = False
+
+    dependencies = [
+        ("zerver", "0382_create_role_based_system_groups"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            revoke_invitations,
+            reverse_code=migrations.RunPython.noop,
+            elidable=True,
+        )
+    ]