Bump pitest-maven from 1.6.7 to 1.6.8

Bumps [pitest-maven](https://github.com/hcoles/pitest) from 1.6.7 to 1.6.8.
- [Release notes](https://github.com/hcoles/pitest/releases)
- [Commits](hcoles/pitest@1.6.7...pitest-parent-1.6.8)

---
updated-dependencies:
- dependency-name: org.pitest:pitest-maven
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

pom.xml

@@ -51,7 +51,7 @@
     <maven-jar-plugin.version>3.2.0</maven-jar-plugin.version>
     <maven-dependency-plugin.version>3.2.0</maven-dependency-plugin.version>
     <maven-resources-plugin.version>3.2.0</maven-resources-plugin.version>
-    <pitest-maven.plugin>1.6.7</pitest-maven.plugin>
+    <pitest-maven.plugin>1.6.8</pitest-maven.plugin>
     <pitest-maven.junit5.plugin>0.14</pitest-maven.junit5.plugin>
     <revapi-maven-plugin.version>0.14.3</revapi-maven-plugin.version>
     <revapi-java.version>0.24.4</revapi-java.version>