Everywhere: Refer to dlfcn*.h by its non-prefixed name

Author: https://github.com/timschumi
Commit: 27bfb81702
Pull-request: https://github.com/SerenityOS/serenity/pull/14854

Userland/Libraries/LibGPU/Driver.cpp

@@ -7,12 +7,8 @@
 #include <AK/HashMap.h>
 #include <AK/String.h>
 #include <AK/WeakPtr.h>
-#ifdef __serenity__
-#    include <LibDl/dlfcn.h>
-#else
-#    include <dlfcn.h>
-#endif
 #include <LibGPU/Driver.h>
+#include <dlfcn.h>
 
 namespace GPU {