New Mineshaft changes are not present outside experiments toggle, unlike Java

When you're generating mineshaft without the experimental toggle, it doesn't generate with the new mineshaft changes. This isn't in parity with Java, where the new mineshaft with chains and logs supports can be generated without experimental datapacks.

Example of it:
1. Use seed 1714946903, generate without experiments toggle.
2. Go to 1497 60 755 and explore the mineshaft