Feat/admin drop user (#10342)

### What problem does this PR solve?

- Admin client support drop user.

Issue: #10241 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

api/db/services/langfuse_service.py

@@ -51,6 +51,11 @@ class TenantLangfuseService(CommonService):
         except peewee.DoesNotExist:
             return None
 
+    @classmethod
+    @DB.connection_context()
+    def delete_ty_tenant_id(cls, tenant_id):
+        return cls.model.delete().where(cls.model.tenant_id == tenant_id).execute()
+
     @classmethod
     def update_by_tenant(cls, tenant_id, langfuse_keys):
         langfuse_keys["update_time"] = current_timestamp()