GROOVY-11574: Bump junit5/platform to 5.12.0/1.12.0

Author: paulk-asert

build.gradle

@@ -157,8 +157,8 @@ ext {
     spotbugsVersion = '4.7.1'
     spotbugsAnnotationsVersion = '4.7.1'
     checkstyleVersion = '8.44'
-    junit5Version = '5.9.2'
-    junit5PlatformVersion = '1.9.2'
+    junit5Version = '5.12.0'
+    junit5PlatformVersion = '1.12.0'
     jcipAnnotationsVersion = '1.0'
     jspApiVersion = '2.3.3'
     servletApiVersion = '4.0.1'