various: mark files with the usual license tags

For .clang-format and pytest.ini, MIT-0 is used because people might want
to copy those.

.github/advanced-issue-labeler.yml

@@ -1,4 +1,4 @@
----
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # syntax - https://github.com/redhat-plumbers-in-action/advanced-issue-labeler#policy
 
 policy:

.github/development-freeze.yml

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # syntax - https://github.com/redhat-plumbers-in-action/devel-freezer#policy
 ---
 

.github/workflows/claude-review.yml

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # Integrates Claude Code as an AI assistant for reviewing pull requests.
 # Mention @claude in any PR comment to request a review. Claude authenticates
 # via AWS Bedrock using OIDC — no long-lived API keys required.

.github/workflows/development-freeze.yml

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # doc: https://github.com/redhat-plumbers-in-action/devel-freezer#readme
 ---
 

.github/workflows/differential-shellcheck.yml

@@ -1,4 +1,4 @@
----
+# SPDX-License-Identifier: LGPL-2.1-or-later
 # https://github.com/redhat-plumbers-in-action/differential-shellcheck#readme
 
 name: Differential ShellCheck

.github/workflows/gather-pr-metadata.yml

@@ -1,4 +1,4 @@
----
+# SPDX-License-Identifier: LGPL-2.1-or-later
 
 name: Gather Pull Request Metadata
 

.github/workflows/issue-labeler.yml

@@ -1,4 +1,4 @@
----
+# SPDX-License-Identifier: LGPL-2.1-or-later
 
 name: Issue labeler
 on:

.github/workflows/make-release.yml

@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
 name: Make a Github release
 
 on: