focuswriter: 1.6.10 -> 1.6.11

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

This update was made based on information from https://repology.org/metapackage/focuswriter/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 1.6.11 with grep in /nix/store/l07yhlav7gx82f378b7pj42bd7mmgrii-focuswriter-1.6.11
- directory tree listing: https://gist.github.com/79fa42f32dce74dd135a983506320802