Disable use of Javassist ProxyFactory cache due to leaks

The ProxyFactory proxy class cache is a broken concept that cannot work in Java unless a global AS service is established and all proxies are created through the service. But that would degrade performance as well.

Since Weld stores the proxy class created for each bean and decorator already, this cache is not actually used. To eliminate the classloader leaks and the heap memory leaks from this cache, it should be disabled every time before a new proxy class is created.