Dependabot (and forks) can't publish to maven snapshot

[StefMa]

Currently our PR failing. They can't publish to the maven snapshot repo. Some problems with signing 👀...
See the dependabot PRs like this #173 and this #176 by @juschmitt.
We should investigate why this happen.

For the dependabot cases it might be due the lack of the secrets. They secrets should be stored in settings -> dependabot (or something) as well.

For the @juschmitt case...i don't know 🤷‍♂️
See next comment 👇

We can also disabling singing because this not required for the snapshot repository (see https://central.sonatype.org/publish/publish-portal-snapshots/). But if the issue is about "can't read the secrets" this wouldn't help either because then they also don't have access to the sonatype user and password that are stored in the secrets 👀.

[StefMa]

Found the problem for #176.
See #176 (comment)

It's about forks doesn't have access to the secrets. Obviously.