style: fix linter issues - black formatting

- Remove extra blank lines
- Use explicit 'is not None' check for registry_pubsub
- Format multi-line function calls per black style

autogpt_platform/backend/backend/api/ws_api.py

@@ -81,7 +81,7 @@ async def event_broadcaster(manager: ConnectionManager):
 
         # Track registry pubsub for cleanup
         from redis.asyncio.client import PubSub
-        
+
         registry_pubsub: PubSub | None = None
 
         async def registry_refresh_worker():
@@ -122,7 +122,7 @@ async def event_broadcaster(manager: ConnectionManager):
         # Ensure PubSub connections are closed on any exit to prevent leaks
         await execution_bus.close()
         await notification_bus.close()
-        if registry_pubsub:
+        if registry_pubsub is not None:
             await registry_pubsub.close()
 
 

autogpt_platform/backend/backend/data/graph.py

@@ -1667,12 +1667,12 @@ async def migrate_llm_models(migrate_to: LlmModel):
     from backend.data import llm_registry
 
     enum_values = list(llm_registry.get_all_model_slugs_for_validation())
-    
+
     # Skip migration if registry is empty (fresh deployment before seeding)
     if not enum_values:
         logger.warning("LLM registry is empty, skipping model migration")
         return
-    
+
     escaped_enum_values = repr(tuple(enum_values))  # hack but works
 
     # Update each block

autogpt_platform/backend/backend/server/v2/llm/db.py

@@ -398,9 +398,7 @@ async def toggle_model(
         # This ensures no nodes are missed between query and update
         async with transaction() as tx:
             # Validate replacement model exists and is enabled (inside transaction to prevent TOCTOU)
-            replacement = await tx.llmmodel.find_unique(
-                where={"slug": migrate_to_slug}
-            )
+            replacement = await tx.llmmodel.find_unique(where={"slug": migrate_to_slug})
             if not replacement:
                 raise ValueError(f"Replacement model '{migrate_to_slug}' not found")
             if not replacement.isEnabled: