[Assist] Package "blender" depends on non-existent "openjpeg"

[bill-auger]

arch has retired 'openjpeg' yesterday - 'openjpeg2' is said to be a
backward-compatible replacement - blender will need to be rebuilt
to accommodate the replacement

https://bugs.archlinux.org/task/66331

'openjpeg' and 'openjpeg2' do not conflict; so you can still install
blender today, if you first install 'openjpeg', like so:

$ sudo pacman -U https://archive.archlinux.org/packages/o/openjpeg/openjpeg-1.5.2-2-x86_64.pkg.tar.xz