chessx: 1.4.0 -> 1.4.6

Semi-automatic update. 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 1.4.6 with grep in /nix/store/9cv1znh739dblr4avnhnp463v77yq9by-chessx-1.4.6
- found 1.4.6 in filename of file in /nix/store/9cv1znh739dblr4avnhnp463v77yq9by-chessx-1.4.6