The CodeQL CLI does not support merging SARIF files. Merging files in the action.

Uploading multiple CodeQL runs with the same category is deprecated and will be removed on June 4, 2025 for CodeQL CLI 2.16.6 and earlier. Please update your CodeQL CLI version or update your workflow to set a distinct category for each CodeQL run. For more information, see https://github.blog/changelog/2024-05-06-code-scanning-will-stop-combining-runs-from-a-single-upload