fix: update trademark on main website (#60)

Author: rchincha

.github/workflows/ci.yml

@@ -6,7 +6,7 @@ on:
       - main
 
 env:
-  PYTHON_VERSION: 3.x
+  PYTHON_VERSION: 3.11
 
 permissions:
   contents: read

docs/concepts/about.md

@@ -32,6 +32,4 @@ The stacker project is hosted on GitHub:
 
 ## License
 
-stacker is released under the Apache License, Version 2.0, and is:
-
-Copyright (C) 2017-2023 Cisco Systems, Inc. and contributors
+stacker is released under the Apache License, Version 2.0

docs/license.md

@@ -4,7 +4,7 @@ site_description: Stacker Build
 repo_url: https://github.com/project-stacker/stacker
 repo_name: project-stacker/stacker
 edit_uri: ""
-copyright: Copyright © 2017 - 2023 Cisco Systems Inc., All Rights Reserved.
+copyright: Copyright &copy; 2017 - 2025 The stacker project authors, All Rights Reserved. | The Linux Foundation® (TLF) has registered trademarks and uses trademarks. For a list of TLF trademarks, see <a href="https://www.linuxfoundation.org/trademark-usage/">Trademark Usage</a>
 theme:
   name: material
   custom_dir: material
@@ -133,6 +133,5 @@ nav:
     - LXC Usage: developer_guide/lxc_usage.md
     - OverlayFS Usage: developer_guide/overlayfs_usage.md
     - Contributing: developer_guide/CONTRIBUTING.md
-  - License: license.md
 extra_css:
   - stylesheets/custom.css