ci: make ignore lists optional for approval

tools/ci/check_codeowners.py

@@ -2,19 +2,8 @@
 #
 # Utility script for ESP-IDF developers to work with the CODEOWNERS file.
 #
-# Copyright 2020 Espressif Systems (Shanghai) PTE LTD
-#
-# 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.
+# SPDX-FileCopyrightText: 2020-2021 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: Apache-2.0
 
 import argparse
 import os
@@ -132,7 +121,10 @@ def action_ci_check(args):
             if line.startswith('# sort-order-reset'):
                 prev_path_pattern = ''
 
-            if not line or line.startswith('#'):
+            if (not line
+                    or line.startswith('#')  # comment
+                    or line.startswith('[')  # file group
+                    or line.startswith('^[')):  # optional file group
                 continue
 
             # Each line has a form of "<path> <owners>+"