ci: fix DeepSource and GitHub Actions security policy failures
- Created .deepsource.toml to resolve DeepSource analyzer errors.
- Pinned all GitHub Actions to full-length commit SHAs across all workflow files to satisfy repository security requirements.
- Updated actions include checkout, setup-python, setup-node, upload-artifact, and several others.
Co-authored-by: OneFineStarstuff <87420139+OneFineStarstuff@users.noreply.github.com>