* feat: support merging humanoid bones with PBs in limited cases
This change adds support for merging humanoid bones that are a target of PhysBones, provided that all humanoid children are excluded from that PhysBone (either with a direct ignores field, or using PB Blocker).
Note: Because this is a significant expansion of support, this will need to wait for a minor release to maintain semver semantics.
Closes: #1406
