[gen-ucd-table] Add another clippy warning

src/gen-ucd-table.py

diff --git a/src/gen-ucd-table.py b/src/gen-ucd-table.py
index 2a48a21..9de9d20 100755
--- a/src/gen-ucd-table.py
+++ b/src/gen-ucd-table.py
@@ -193,7 +193,7 @@
     print("pub(crate) mod ucd {")
     print()
     print("#![allow(unused_parens)]")
-    print("#![allow(clippy::unnecessary_cast)]")
+    print("#![allow(clippy::unnecessary_cast, clippy::unreadable_literal)]")
     print()
     print("use crate::hb::algs::{HB_CODEPOINT_ENCODE3, HB_CODEPOINT_ENCODE3_11_7_14};")
     print("use crate::hb::common::script;")