Fix compilation for GCC 13 (#961)

CXX-2686

Author: kkloberdanz

src/mongocxx/events/heartbeat_failed_event.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <cstdint>
+
 #include <bsoncxx/stdx/string_view.hpp>
 
 #include <mongocxx/config/prelude.hpp>

src/mongocxx/events/heartbeat_started_event.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <cstdint>
+
 #include <bsoncxx/stdx/string_view.hpp>
 
 #include <mongocxx/config/prelude.hpp>

src/mongocxx/events/server_closed_event.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <cstdint>
+
 #include <bsoncxx/oid.hpp>
 #include <bsoncxx/stdx/string_view.hpp>
 

src/mongocxx/events/server_opening_event.hpp

@@ -14,6 +14,8 @@
 
 #pragma once
 
+#include <cstdint>
+
 #include <bsoncxx/oid.hpp>
 
 #include <mongocxx/config/prelude.hpp>

src/mongocxx/exception/error_code.hpp

@@ -14,6 +14,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <system_error>
 
 #include <mongocxx/config/prelude.hpp>

src/mongocxx/exception/server_error_code.hpp

@@ -14,6 +14,7 @@
 
 #pragma once
 
+#include <cstdint>
 #include <system_error>
 
 #include <mongocxx/config/prelude.hpp>