[config] Disable buffer serialize routines in HB_TINY

Part of https://github.com/harfbuzz/harfbuzz/issues/1652
diff --git a/src/hb-config.hh b/src/hb-config.hh
index e7e14df..2eab7d8 100644
--- a/src/hb-config.hh
+++ b/src/hb-config.hh
@@ -45,6 +45,7 @@
 #ifdef HB_LEAN
 #define HB_DISABLE_DEPRECATED
 #define HB_NO_ATEXIT
+#define HB_NO_BUFFER_SERIALIZE
 #define HB_NO_BITMAP
 #define HB_NO_CFF
 #define HB_NO_COLOR