[BugFix] Fix scheduler problems in last PR. (#558)

This PR Fixes scheduler problems in last PR:
1. change position of DT test to validate it.
2. fix format of copyright.

Signed-off-by: whx-sjtu <2952154980@qq.com>

vllm_ascend/core/scheduler.py

@@ -1,3 +1,19 @@
+#
+# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# This file is a part of the vllm-ascend project.
+#
 from collections import deque
 
 from vllm.logger import init_logger