[bot]: Bump org.pitest:pitest-maven from 1.14.4 to 1.15.3

Bumps [org.pitest:pitest-maven](https://github.com/hcoles/pitest) from 1.14.4 to 1.15.3.
- [Release notes](https://github.com/hcoles/pitest/releases)
- [Commits](hcoles/pitest@1.14.4...1.15.3)

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

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

build/optaplanner-build-parent/pom.xml

@@ -79,7 +79,7 @@
     -->
     <version.javadoc.plugin>3.5.0</version.javadoc.plugin>
     <version.jaxb2.plugin>2.5.0</version.jaxb2.plugin>
-    <version.pitest.plugin>1.14.4</version.pitest.plugin>
+    <version.pitest.plugin>1.15.3</version.pitest.plugin>
     <version.revapi.plugin>0.15.0</version.revapi.plugin>
     <version.sniffer.plugin>1.23</version.sniffer.plugin>
     <version.surefire.plugin>3.0.0</version.surefire.plugin>