adapt release drafter config to have smaller github release notes

[atomfrede]

With this configuration dependabot PRs are excluded and only PRs with label "release-notes" (must be added manually to a PR) are added to release notes. Hope this works now, at least thats what the documentation says.

Relates too #18319

---

Please make sure the below checklist is followed for Pull Requests.

• All continuous integration tests are green
• Tests are added where necessary
• The JDL part is updated if necessary
• jhipster-online is updated if necessary
• Documentation is added/updated where necessary
• Coding Rules & Commit Guidelines as per our CONTRIBUTING.md document are followed

When you are still working on the PR, consider converting it to Draft (below reviewers) and adding skip-ci label, you can still see CI build result at your branch.