Keep GitHub Actions up to date with GitHub's Dependabot

[cclauss]

Fixes software supply chain safety warnings like at the bottom right of https://github.com/tsutsu3/linkify-it-py/actions/runs/7774829721

• Keeping your actions up to date with Dependabot
• Configuration options for the dependabot.yml file - package-ecosystem

[tsutsu3]

thanks 😄

[cclauss]

Generated:

• 62