temporarily disable serializable transactions

until this can get figured out better

capsulflask/db_model.py

@@ -361,7 +361,8 @@ class DBModel:
   def claim_operation(self, operation_id: int, host_id: str) -> bool:
     # have to make a new cursor to set isolation level
     # cursor = self.connection.cursor()
-    self.cursor.execute("SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;")
+    # self.cursor.execute("SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;")
+    # psycopg2.errors.ActiveSqlTransaction: SET TRANSACTION ISOLATION LEVEL must be called before any query
     self.cursor.execute("""
       BEGIN TRANSACTION;
       UPDATE host_operation SET assignment_status = 'assigned'