openimageio: 1.7.17 -> 1.8.8

Semi-automatic update. These checks were performed:

- built on NixOS
- ran `/nix/store/fmwizi71ki95gjzqrbcc64zspg3xik6d-openimageio-1.8.8-bin/bin/iinfo help` got 0 exit code
- ran `/nix/store/fmwizi71ki95gjzqrbcc64zspg3xik6d-openimageio-1.8.8-bin/bin/maketx -v` and found version 1.8.8
- ran `/nix/store/fmwizi71ki95gjzqrbcc64zspg3xik6d-openimageio-1.8.8-bin/bin/oiiotool --help` got 0 exit code
- ran `/nix/store/fmwizi71ki95gjzqrbcc64zspg3xik6d-openimageio-1.8.8-bin/bin/oiiotool --help` and found version 1.8.8
- found 1.8.8 with grep in /nix/store/fmwizi71ki95gjzqrbcc64zspg3xik6d-openimageio-1.8.8-bin
- found 1.8.8 in filename of file in /nix/store/fmwizi71ki95gjzqrbcc64zspg3xik6d-openimageio-1.8.8-bin

cc "@goibhniu"