fix: compute bastion variants correctly for 1.16.1

[alex-chew]

In Minecraft 1.16.1, a bastion's variant is sampled from its ChunkRandom before its rotation is sampled, not the other way around (as is so for 1.16.2 and above). I tested this on 10 or so bastions in 1.16.1 versus 1.16.2, and this PR fixes the computed bastion variants for 1.16.1.

[Cubitect]

Thanks, but unfortunately I don't have the time or motivation to support each minor version, which is why cubiomes only supports the latest patch of each major version. Minor patches actually change things like that fairly frequently, and supporting 1.16.1 without all the other minor patches of all versions doesn't make too much sense.

[Cubitect]

Some groundwork has now been done to support minor versions and, although the development focus will remain with the latest patch for each major release, this Bastion rotation fix is now included.

[alex-chew]

Thanks, glad to hear it!