Spring Deprecate and remove use of UrlPathHelper in ServletWebSocketHandlerRegistry

Spring Security is preparing to adapt to the PathMatcher deprecations in spring-web, see https://github.com/spring-projects/spring-security/pull/16499. A question came up how to adapt to the deprecation of UrlPathHelper use in ServletWebSocketHandlerRegistry.

The WebSocketHandlerMapping is created internally, and there is no mechanism to customize it. Therefore, after PathPatternParser became the default, the UrlPathHelper property is effectively no longer used. We can fastrack its removal in 7.0 with an immediate deprecation in 6.2.x.