minetest: minetest-mod-player-3d-armor renamed to minetest-mod-3d-armor

For Minetest, currently we list minetest-mod-player-3d-armor as a package. Since the package has been renamed to minetest-mod-3d-armor in Bookworm, it is not installable there.

We could simply rename the required package in the list, but it raises the following questions:

1. The package is still named minetest-mod-player-3d-armor in Bullseye. Do we set the name dynamically based on the current distro, or patch the name for bullseye-backports?
2. Can the package get installed during Bullseye -> Bookworm dist upgrade?
3. Should Packages component have a concept of "optional" packages, or perhaps "alternatives"?