Start building against Spring Framework 6.2.12 snapshots

See gh-47462

Author: snicoll

gradle.properties

@@ -19,7 +19,7 @@ mavenVersion=3.9.10
 mockitoVersion=5.17.0
 nativeBuildToolsVersion=0.10.6
 snakeYamlVersion=2.4
-springFrameworkVersion=6.2.11
+springFrameworkVersion=6.2.12-SNAPSHOT
 springFramework60xVersion=6.0.23
 tomcatVersion=10.1.46