fix: include gas costs call in base fork transition

Author: Carsons-Eels

packages/testing/src/execution_testing/forks/transition_base_fork.py

@@ -90,7 +90,10 @@ def transition_method(
 
             return classmethod(transition_method)
 
-        for method_name in base_fork_abstract_methods() + ["bpo_fork"]:
+        for method_name in base_fork_abstract_methods() + [
+            "bpo_fork",
+            "gas_costs",
+        ]:
             setattr(
                 NewTransitionClass,
                 method_name,