Revert "Upgrade to Kotlin 2.2.20"

This reverts commit 3dbbd6d.

See spring-projects/spring-framework#35487
See gh-47148

Author: snicoll

gradle.properties

@@ -15,7 +15,7 @@ jackson2Version=2.20.0
 jacksonVersion=3.0.0-rc9
 javaFormatVersion=0.0.47
 junitJupiterVersion=5.13.4
-kotlinVersion=2.2.20
+kotlinVersion=2.2.10
 mavenVersion=3.9.10
 mockitoVersion=5.19.0
 nativeBuildToolsVersion=0.11.0