Remove the `use_hidden` parameter of the `BKE_pose_minmax()` function.
This parameter was only used with `use_selected` set to the same value,
with the following effects:
- Both set to `true`: only selected bones are considered. Since hidden
bones are automatically deselected, this effectively excluded hidden
bones.
- Both set to `false`: explicitly excludes hidden bones.
So in both use cases hidden bones were ignored, which IMO is the correct
approach anyway, as the bounding box is used for centering in view,
snapping to bounding box, etc.
No functional changes.
b4cc9329e5