WIP: Test ITKClangFormatLinterAction composite-action branch (clean code)

Temporary PR to validate PR #23 of ITKClangFormatLinterAction.
This branch has no clang-format violations — expect PASS.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hjmjohnson

.github/workflows/clang-format-linter.yml

@@ -9,6 +9,6 @@ jobs:
     steps:
     - uses: actions/checkout@v5
 
-    - uses: InsightSoftwareConsortium/ITKClangFormatLinterAction@main
+    - uses: InsightSoftwareConsortium/ITKClangFormatLinterAction@composite-action
       with:
         itk-branch: main