Add explicit <cstdlib> include to Range.hpp (#24918)

LLVM libc++ 21 shuffled around some includes internally, causing cstdlib
to no longer be transitively included here. Explicitly include it for
size_t.

src/openrct2/core/Range.hpp

@@ -10,6 +10,7 @@
 #pragma once
 
 #include <cmath>
+#include <cstdlib>
 #include <type_traits>
 
 template<typename T>