graphicsmagick: 1.3.29 -> 1.3.30 (#42704)

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

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

These checks were done:

- built on NixOS
- /nix/store/kws698xdnjfrl70gi5gvp4f90i00w35p-graphicsmagick-1.3.30/bin/gm passed the binary check.
- /nix/store/kws698xdnjfrl70gi5gvp4f90i00w35p-graphicsmagick-1.3.30/bin/GraphicsMagick++-config passed the binary check.
- /nix/store/kws698xdnjfrl70gi5gvp4f90i00w35p-graphicsmagick-1.3.30/bin/GraphicsMagick-config passed the binary check.
- /nix/store/kws698xdnjfrl70gi5gvp4f90i00w35p-graphicsmagick-1.3.30/bin/GraphicsMagickWand-config passed the binary check.
- 4 of 4 passed binary check by having a zero exit code.
- 3 of 4 passed binary check by having the new version present in output.
- found 1.3.30 with grep in /nix/store/kws698xdnjfrl70gi5gvp4f90i00w35p-graphicsmagick-1.3.30
- directory tree listing: https://gist.github.com/e51d94d9d1da3d8ccfb7359a7d6e7655
- du listing: https://gist.github.com/e1a40fb5a980660ff689d25e98d20d18