openimageio: 1.8.8 -> 1.8.9

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

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

These checks were done:

- built on NixOS
- ran `/nix/store/p493iy79axka02qddq8zn8ki9qxv89lr-openimageio-1.8.9-bin/bin/iinfo help` got 0 exit code
- ran `/nix/store/p493iy79axka02qddq8zn8ki9qxv89lr-openimageio-1.8.9-bin/bin/maketx -v` and found version 1.8.9
- ran `/nix/store/p493iy79axka02qddq8zn8ki9qxv89lr-openimageio-1.8.9-bin/bin/oiiotool --help` got 0 exit code
- ran `/nix/store/p493iy79axka02qddq8zn8ki9qxv89lr-openimageio-1.8.9-bin/bin/oiiotool --help` and found version 1.8.9
- found 1.8.9 with grep in /nix/store/p493iy79axka02qddq8zn8ki9qxv89lr-openimageio-1.8.9-bin
- directory tree listing: https://gist.github.com/171d660967f6995b3e6107258782e390