Add/Format License/Copyright headers (#6128)

### Description
<!-- - Describe your changes. -->

### Motivation and Context
<!-- - Why is this change required? What problem does it solve? -->
<!-- - If it fixes an open issue, please link to the issue here. -->

Signed-off-by: Dr. Andreas Fehlner <fehlner@arcor.de>

.github/workflows/dco_merge_group.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 name: DCO
 on:
   merge_group:

.github/workflows/main.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 name: CI
 
 on:

.github/workflows/release_win.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 name: WindowsRelease
 
 on:

.github/workflows/scorecard.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # This workflow uses actions that are not certified by GitHub. They are provided
 # by a third-party and are governed by separate terms of service, privacy
 # policy, and support documentation.

.github/workflows/stale.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # This workflow warns and then closes issues and PRs that have had no activity for a specified amount of time.
 #
 # You can adjust the behavior by modifying this file.

.github/workflows/weekly_mac_ci.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 # Weekly ci workflow for model zoo.
 # Runs model checker/shape_inference/version_converter for all models
 name: Weekly CI with the latest ONNX and ONNX Model Zoo

.github/workflows/win_no_exception_ci.yml

@@ -1,3 +1,7 @@
+# Copyright (c) ONNX Project Contributors
+#
+# SPDX-License-Identifier: Apache-2.0
+
 name: Windows_No_Exception_CI
 
 on:

CONTRIBUTING.md

@@ -1,8 +1,8 @@
 <!--
 Copyright (c) ONNX Project Contributors
--->
 
-<!--- SPDX-License-Identifier: Apache-2.0 -->
+SPDX-License-Identifier: Apache-2.0
+-->
 
 # ONNX Community Involvement and Contribution Guidelines
 

README.md

@@ -1,8 +1,8 @@
 <!--
 Copyright (c) ONNX Project Contributors
--->
 
-<!--- SPDX-License-Identifier: Apache-2.0 -->
+SPDX-License-Identifier: Apache-2.0
+-->
 
 <p align="center"><img width="40%" src="https://github.com/onnx/onnx/raw/main/docs/onnx-horizontal-color.png" /></p>
 

RELEASE-MANAGEMENT.md

@@ -1,8 +1,8 @@
 <!--
 Copyright (c) ONNX Project Contributors
--->
 
-<!--- SPDX-License-Identifier: Apache-2.0 -->
+SPDX-License-Identifier: Apache-2.0
+-->
 
 # ONNX release management
 

SECURITY.md

@@ -1,8 +1,8 @@
 <!--
 Copyright (c) ONNX Project Contributors
--->
 
-<!--- SPDX-License-Identifier: Apache-2.0 -->
+SPDX-License-Identifier: Apache-2.0
+-->
 
 # Security Policy