fix: missing header when compile using gcc 15

Author: proost

common/include/serde.hpp

@@ -20,6 +20,7 @@
 #ifndef DATASKETCHES_SERDE_HPP_
 #define DATASKETCHES_SERDE_HPP_
 
+#include <cstdint>
 #include <cstring>
 #include <iostream>
 #include <memory>

fi/include/reverse_purge_hash_map.hpp

@@ -20,8 +20,9 @@
 #ifndef REVERSE_PURGE_HASH_MAP_HPP_
 #define REVERSE_PURGE_HASH_MAP_HPP_
 
-#include <memory>
+#include <cstdint>
 #include <iterator>
+#include <memory>
 
 namespace datasketches {