Subject: [PATCH] gif_hash.c: include <stdlib.h> for malloc and free

GCC 14 turns implicit function declarations into errors, so the build
stops at gif_hash.c. giflib 5.x already includes <stdlib.h> here.

---
--- a/lib/gif_hash.c
+++ b/lib/gif_hash.c
@@ -20,6 +20,7 @@
 #include <stdint.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "gif_lib.h"