Configure repository to use dependabot

[marcoesters]

Checklist

• I added a descriptive title
• I searched open requests and couldn't find a duplicate

What is the idea?

Configure this repository to use dependabot to keep dependencies up-to-date and update existing dependencies.

Why is this needed?

The canary build actions uses an outdated version, which in turn calls a version of setup-miniconda that breaks on MacOS. This could have been avoided with automatic updates using dependabot.

What should happen?

Dependabot should be added to the repository and dependencies should be pinned using the commit hash.

Additional Context

No response