Start building against Spring Framework 6.1.4 snapshots

See gh-39481

Author: wilkinsona

gradle.properties

@@ -13,7 +13,7 @@ junitJupiterVersion=5.10.1
 kotlinVersion=1.9.22
 mavenVersion=3.9.4
 nativeBuildToolsVersion=0.9.28
-springFrameworkVersion=6.1.3
+springFrameworkVersion=6.1.4-SNAPSHOT
 tomcatVersion=10.1.18
 
 kotlin.stdlib.default.dependency=false