add missing license

Author: chestm007

src/zepben/evolve/services/network/tracing/networktrace/network_trace_action_type.py

@@ -1,7 +1,9 @@
-from abc import abstractmethod
+#  Copyright 2024 Zeppelin Bend Pty Ltd
+#  This Source Code Form is subject to the terms of the Mozilla Public
+#  License, v. 2.0. If a copy of the MPL was not distributed with this
+#  file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
 from enum import Enum, member
-from functools import partial
-from typing import Callable
 
 from zepben.evolve.services.network.tracing.networktrace.network_trace_step import NetworkTraceStep
 from zepben.evolve.services.network.tracing.traversal.step_context import StepContext