fix: refine 0002 migration file

djangocms_version_locking/migrations/0002_migrate_locked_by.py

@@ -1,20 +1,21 @@
 # Generated by Django 4.2.8 on 2024-11-07 07:21
 
-from django.db import migrations
+from django.db import migrations, transaction
 
 
 def forwards(apps, schema_editor):
     db_alias = schema_editor.connection.alias
     Version = apps.get_model("djangocms_versioning", "Version")
     VersionLock = apps.get_model("djangocms_version_locking", "VersionLock")
 
-    version_qs = Version.objects.using(db_alias).all()
     version_lock_qs = VersionLock.objects.using(db_alias).all()
-    for lock_item in version_lock_qs:
-        locked_version = version_qs.filter(pk=lock_item.version.pk)
-        if locked_version:
-            locked_version.locked_by = lock_item.created_by
-            locked_version.save()
+    versions = set(Version.objects.using(db_alias).filter(pk__in=version_lock_qs.values('version')))
+
+    with transaction.atomic():
+        for version in versions:
+            version.locked_by = version.versionlock.created_by
+
+    Version.objects.using(db_alias).bulk_update(versions, ['locked_by']) 
 
 
 class Migration(migrations.Migration):