fix SQLAlchemy queries

Author: fregataa

src/ai/backend/manager/repositories/permission_controller/db_source.py

@@ -140,10 +140,10 @@ async def check_scope_permission_exist(
         scope_id: ScopeId,
         operation: OperationType,
     ) -> bool:
-        role_query = (
-            sa.select(sa.func.exist())
+        exist_query = sa.exists(
+            sa.select(1)
             .select_from(
-                sa.join(UserRoleRow, RoleRow.id == UserRoleRow.role_id)
+                sa.join(UserRoleRow, RoleRow, RoleRow.id == UserRoleRow.role_id)
                 .join(PermissionGroupRow, RoleRow.id == PermissionGroupRow.role_id)
                 .join(PermissionRow, PermissionGroupRow.id == PermissionRow.permission_group_id)
             )
@@ -158,12 +158,8 @@ async def check_scope_permission_exist(
                     PermissionRow.operation == operation,
                 )
             )
-            .options(
-                contains_eager(RoleRow.permission_group_rows).options(
-                    selectinload(PermissionGroupRow.permission_rows)
-                )
-            )
         )
+        role_query = sa.select(exist_query)
         async with self._db.begin_readonly_session() as db_session:
             result = await db_session.scalar(role_query)
             return result