utf8proc: 2.1.0 -> 2.1.1

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

This update was made based on information from https://repology.org/metapackage/utf8proc/versions.

These checks were done:

- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- found 2.1.1 with grep in /nix/store/bzpfz4cpf1lf7269ymwdblz2kn0iwf2b-utf8proc-2.1.1
- directory tree listing: https://gist.github.com/bc9fd69cddc0fd9435fab30a0abcae97