ci: add auto merge workflow for dependabot PRs

[amimart]

🤖 Dependabot auto merge

• [x] I've read the last version of CODE_OF_CONDUCT.md and CONTRIBUTING.md

Description

Add an auto merge github actions workflow which will merge automatically dependabot PRs concerning minor & patch version updates.

Testing

This recipe is already used elsewhere and seems to work, let's try it.

[bot-anik]

:tada: This PR is included in version 2.0.0 :tada:

The release is available on GitHub release

Your semantic-release bot :package::rocket: