Update dependency org.mockito:mockito-core to v5.15.2

Author: renovate[bot]

gradle/libs.versions.toml

@@ -6,7 +6,7 @@ hivemq-extensionSdk = "4.7.5"
 jetbrains-annotations = "26.0.1"
 junit-jupiter = "5.10.0"
 logback = "1.5.15"
-mockito = "5.14.2"
+mockito = "5.15.2"
 owner = "1.0.12"
 testcontainers = "1.20.4"