Add copyright notice to envsetup.sh

Author: PLeVasseur

build/envsetup.sh

@@ -1,5 +1,16 @@
 #!/bin/bash
 #
+# Copyright (c) 2025 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# SPDX-License-Identifier: Apache-2.0
+#
 # to set environment variables for c++ stdlib paths:
 # $ source build/envsetup.sh 
 #