Keep GitHub Actions up to date with GitHub's Dependabot

[cclauss]

Fixes software supply chain safety warnings like on the bottom right of https://github.com/cclauss/Personal-Digital-Assistant/actions/runs/8520371449

Keeping your actions up to date with Dependabot

Configuration options for the dependabot.yml file - package-ecosystem

• https://github.com/actions/setup-python/releases
• https://github.com/actions/upload-artifact/releases
• https://github.com/github/codeql-action/releases

@arthaud @0xedward Your reviews, please.