harfbuzz-icu: 1.8.0 -> 1.8.1

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/harfbuzz-icu/versions.

These checks were done:

- built on NixOS

- 0 of 0 passed binary check by having a zero exit code.
- 0 of 0 passed binary check by having the new version present in output.
- found 1.8.1 with grep in /nix/store/419wp0z2096xs6kp9zlj20hys61clnay-harfbuzz-icu-1.8.1
- directory tree listing: https://gist.github.com/e7c8b4aebf0715a6aee75d6fe6d3e8e1
- du listing: https://gist.github.com/ff39237157e9c975f8c6d8a66326c6b7