shards: 0.8.0 -> 0.8.1 (#42444)

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

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

These checks were done:

- built on NixOS
- /nix/store/b67b2aq0jfy3mmvb3nvz40jx1ngkkg5c-shards-0.8.1/bin/shards passed the binary check.
- 1 of 1 passed binary check by having a zero exit code.
- 0 of 1 passed binary check by having the new version present in output.
- found 0.8.1 with grep in /nix/store/b67b2aq0jfy3mmvb3nvz40jx1ngkkg5c-shards-0.8.1
- directory tree listing: https://gist.github.com/a3f46fb5f7b8b4f3120256553c24abd7
- du listing: https://gist.github.com/65b9cb67bb536055ff79ee577f5ec3dc