Include cstdint for compatibility with GCC 15

pastalian · pastalian · commit c7fb53bf3fb2 · 2024-12-28T22:02:06.000+09:00
cstdint needs to be included explicitly since GCC 15. https://gcc.gnu.org/gcc-15/porting_to.html
diff --git a/third_party/msgpack11/msgpack11.hpp b/third_party/msgpack11/msgpack11.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstdint>
 #include <string>
 #include <vector>
 #include <map>
