Update dependency org.pitest:pitest-maven to v1.15.8

Author: renovate[bot]

pom.xml

@@ -354,7 +354,7 @@
             <plugin>
                 <groupId>org.pitest</groupId>
                 <artifactId>pitest-maven</artifactId>
-                <version>1.15.7</version>
+                <version>1.15.8</version>
                 <configuration>
                     <verbose>true</verbose>
                     <targetClasses>