Fix missing #include.

--- libodfgen-0.1.8/src/OdfGenerator.cxx	2021-01-06 10:16:44.000000000 +0000
+++ libodfgen-0.1.8/src/OdfGenerator.cxx	2025-05-03 22:24:51.047389837 +0100
@@ -37,6 +37,7 @@
 #include <memory>
 #include <string>
 #include <stack>
+#include <cstdint>
 
 #include <librevenge/librevenge.h>