libivykis: 0.41 -> 0.42.1

Semi-automatic update. These checks were performed:

- built on NixOS
- found 0.42.1 with grep in /nix/store/npgsv4dlpgkbm8r2rz1wqns7ispcq4na-libivykis-0.42.1
- found 0.42.1 in filename of file in /nix/store/npgsv4dlpgkbm8r2rz1wqns7ispcq4na-libivykis-0.42.1

cc "@rickynils"