fix: avoid duplicate copyright notices

Author: jskeet

.librarian/generator-input/client-post-processing/avoid-double-copyright.yaml

@@ -0,0 +1,62 @@
+# Copyright 2026 Google LLC
+#
+# 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.
+description: Mitigate synthtool adding a second copyright notice when one already exists
+url: https://github.com/googleapis/librarian/issues/4322
+replacements:
+  - paths: [
+      packages/googleapis-common-protos/google/gapic/metadata/gapic_metadata_pb2.pyi,
+      packages/googleapis-common-protos/google/longrunning/operations_proto_pb2.pyi
+    ]
+    before: |
+      # Copyright 2025 Google LLC
+      #
+      # 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.\n
+      # Copyright 2025 Google LLC
+      #
+      # 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.
+    after: |
+      # Copyright 2025 Google LLC
+      #
+      # 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.
+    count: 2