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

CodeQL Action versions 3.25.0 and later, and versions 2.25.0 and later no longer install Python dependencies. We recommend upgrading to at least CodeQL Bundle 2.16.0 to avoid any potential problems due to this (you are currently using 2.12.6). Alternatively, we recommend downgrading the CodeQL Action to version 3.24.10 (for customers using GitHub.com or GitHub Enterprise Server v3.12 or later) or 2.24.10 (for customers using GitHub Enterprise Server v3.11 or earlier).