Update to Spring Framework 6.0.15

Closes gh-1480

gradle.properties

@@ -2,7 +2,7 @@ version=1.1.4-SNAPSHOT
 org.gradle.jvmargs=-Xmx3g -XX:+HeapDumpOnOutOfMemoryError
 org.gradle.parallel=true
 org.gradle.caching=true
-springFrameworkVersion=6.0.13
+springFrameworkVersion=6.0.15
 springSecurityVersion=6.1.5
 springJavaformatVersion=0.0.38
 springJavaformatExcludePackages=org/springframework/security/config org/springframework/security/oauth2