Update dependency org.pitest:pitest to v1.20.3

Author: renovate[bot]

build.gradle

@@ -244,7 +244,7 @@ def versions = [
   springBoot      : '3.5.5',
   springDoc       : '2.8.13',
   camunda         : '7.23.0',
-  pitest          : '1.19.6',
+  pitest          : '1.20.3',
   sonarPitest     : '0.5'
 
 ]