Bump grgit-core from 4.+ to 5.0.0

Bumps [grgit-core](https://github.com/ajoberstar/grgit) from 4.+ to 5.0.0.
- [Release notes](https://github.com/ajoberstar/grgit/releases)
- [Commits](https://github.com/ajoberstar/grgit/commits/5.0.0)

---
updated-dependencies:
- dependency-name: org.ajoberstar.grgit:grgit-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -55,5 +55,5 @@ dependencies {
     api 'org.sonarsource.scanner.gradle:sonarqube-gradle-plugin:3.2.0'
     implementation 'gradle.plugin.net.wooga.gradle:atlas-github:2.+'
     testImplementation 'com.wooga.spock.extensions:spock-github-extension:0.2.0'
-    testImplementation 'org.ajoberstar.grgit:grgit-core:4.+'
+    testImplementation 'org.ajoberstar.grgit:grgit-core:5.+'
 }