gmic: 1.7.9 -> 2.2.0

Semi-automatic update. These checks were done:

- built on NixOS
- ran `/nix/store/akcdj31wk383lglx9afg3vyyilvfmbnb-gmic-2.2.0/bin/gmic --version` and found version 2.2.0
- ran `/nix/store/akcdj31wk383lglx9afg3vyyilvfmbnb-gmic-2.2.0/bin/gmic version` and found version 2.2.0
- found 2.2.0 in filename of file in /nix/store/akcdj31wk383lglx9afg3vyyilvfmbnb-gmic-2.2.0