Ensure successful CI from forks

[markusdregi]

I made both CircleCI and Codacy non-required as neither runs successfully on project forks. The CircleCI settings seems to be correct as is 🤔 But maybe we should just convert to GitHub actions instead of using CircleCI?

For Codacy I've yet to have a look.

Definition of done

• All steps in the CI pipeline is required and
• the CI pipeline launches on branches from external forks.