Userland: Remove workarounds for LibIPC include order sensitivity

Author: https://github.com/trflynn89
Commit: 4fd9e3ab08
Pull-request: https://github.com/SerenityOS/serenity/pull/16081
Issue: https://github.com/SerenityOS/serenity/issues/9584
Reviewed-by: https://github.com/linusg ✅

Userland/Services/RequestServer/ConnectionFromClient.h

@@ -7,8 +7,6 @@
 #pragma once
 
 #include <AK/HashMap.h>
-// Need to include this before RequestClientEndpoint.h as that one includes LibIPC/(De En)coder.h, which would bomb if included before this.
-#include <LibCore/Proxy.h>
 #include <LibIPC/ConnectionFromClient.h>
 #include <RequestServer/Forward.h>
 #include <RequestServer/RequestClientEndpoint.h>