Handle Request to Prevent Exceptions

[ngocnhan-tran1996]

Related: gh-18157

1. With PathPatternRequestMatcher

   If we define a bean like the one below:

   @Bean
   WebSecurityCustomizer configureWebSecurity() {
       return customizer -> customizer.ignoring()
           .requestMatchers(PathPatternRequestMatcher.withDefaults().matcher("/test/**"));
   }

   an exception will occur because PathPatternRequestMatcher invokes ServletRequestPathUtils#parseAndCache(request):

   java.lang.UnsupportedOperationException: public abstract void jakarta.servlet.ServletRequest.setAttribute(java.lang.String, java.lang.Object) is not supported
   

2. Request#getServletContext can be null, so we need to perform a null check before invoking the apply method.

[lrozenblyum]

Just wondering, will FilterChainProxy.getFilters return anything useful now or it will be always empty?

[rwinch]

Thanks for the PR @ngocnhan-tran1996 I'm closing this because, as pointed out above, it is incorrect to always return false when the ServletContext is null.