WindowServer: Tighten pledged promises

Author: https://github.com/bugreport0
Commit: https://github.com/SerenityOS/serenity/commit/99e0b69c0cc
Pull-request: https://github.com/SerenityOS/serenity/pull/11234
Reviewed-by: https://github.com/alimpfard

Userland/Services/WindowServer/main.cpp

@@ -31,6 +31,7 @@ ErrorOr<int> serenity_main(Main::Arguments)
     act.sa_flags = SA_NOCLDWAIT;
     act.sa_handler = SIG_IGN;
     TRY(Core::System::sigaction(SIGCHLD, &act, nullptr));
+    TRY(Core::System::pledge("stdio video thread sendfd recvfd accept rpath wpath cpath unix proc"));
 
     auto wm_config = Core::ConfigFile::open("/etc/WindowServer.ini");
     auto theme_name = wm_config->read_entry("Theme", "Name", "Default");