Update mockito monorepo to v5.15.2

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 kotlin = "2.1.0"
 jackson = "2.18.2"
 reactor = "3.7.1"
-mockito = "5.14.2"
+mockito = "5.15.2"
 
 [libraries]
 lombok = { module = "org.projectlombok:lombok", version = "1.18.36" }