asymptote: 2.41 -> 2.42

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

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

These checks were done:

- built on NixOS
- ran ‘/nix/store/2qw7zf6brwdbj56dbrn9342s3l51j2d1-asymptote-2.42/bin/asy -h’ got 0 exit code
- ran ‘/nix/store/2qw7zf6brwdbj56dbrn9342s3l51j2d1-asymptote-2.42/bin/asy --help’ got 0 exit code
- found 2.42 with grep in /nix/store/2qw7zf6brwdbj56dbrn9342s3l51j2d1-asymptote-2.42
- directory tree listing: https://gist.github.com/ea517431d1ae476366452121c7871132