hdparm: 9.55 -> 9.56

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

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

These checks were done:

- built on NixOS
- ran `/nix/store/c646kg7w31rm3rz30n145jf77kjw2dmg-hdparm-9.56/bin/hdparm -h` got 0 exit code
- ran `/nix/store/c646kg7w31rm3rz30n145jf77kjw2dmg-hdparm-9.56/bin/hdparm -V` and found version 9.56
- ran `/nix/store/c646kg7w31rm3rz30n145jf77kjw2dmg-hdparm-9.56/bin/hdparm -h` and found version 9.56
- found 9.56 with grep in /nix/store/c646kg7w31rm3rz30n145jf77kjw2dmg-hdparm-9.56
- directory tree listing: https://gist.github.com/288d8bff26d3af52b38fbd8055ee2aac