Update spring core to v6.2.15

Author: renovate[bot]

gradle/libs.versions.toml

@@ -12,7 +12,7 @@ javapoet = "1.13.0"
 jupiter = "6.0.1"
 mapstruct = "1.4.0.Final"
 mockito = "5.21.0"
-spring = "6.0.0"
+spring = "6.2.15"
 springBoot = "3.5.8"
 springDependencyManagement = "1.1.7"
 versionsPlugin = "0.53.0"