reformat migration with black

src/paperless_mail/migrations/0013_merge_20220412_1051.py

@@ -6,9 +6,8 @@ from django.db import migrations
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('paperless_mail', '0009_alter_mailrule_action_alter_mailrule_folder'),
-        ('paperless_mail', '0012_alter_mailrule_assign_tags'),
+        ("paperless_mail", "0009_alter_mailrule_action_alter_mailrule_folder"),
+        ("paperless_mail", "0012_alter_mailrule_assign_tags"),
     ]
 
-    operations = [
-    ]
+    operations = []