Bump org.apache.maven.plugins:maven-gpg-plugin from 3.2.7 to 3.2.8 - #1492

[Linkspector] reported by reviewdog 🐶 Cannot reach https://martinfowler.com/bliki/GivenWhenThen.html Status: null Navigation timeout of 30000 ms exceeded Raw Output: message:"Cannot reach https://martinfowler.com/bliki/GivenWhenThen.html Status: null Navigation timeout of 30000 ms exceeded" location:{path:"doc/Testen.md" range:{start:{line:39 column:1} end:{line:39 column:79}}} severity:ERROR source:{name:"linkspector" url:"https://github.com/UmbrellaDocs/linkspector"}