urweb: Fix icu headers include path

Since https://github.com/NixOS/nixpkgs/pull/62266
urweb fails to resolve <unicode/utypepes.h> in runtime (during
compilation of project).
upstream commit: https://github.com/urweb/urweb/commit/c2a217f9121dd865122bc6150c53e77bd662050d

resolves #79218