With c20bb31325 the `active_vert` related
methods added a check against the relevant pbvh type. In certain
situations, the PBVH is freed but is not refreshed prior to the cursor
being drawn.
In the long term, we want the PBVH to be owned by the mesh, not the
`SculptSession`, so adding more logic around ensuring depsgraph tags
with PBVH changes to implicitly regenerate the PBVH is a step in the
wrong direction.
Additionally, it doesn't make sense that we don't ensure the PBVH exists
before accessing the `active_vert`, as its context is dependent on the
PBVH.
Therefore, this commit introduces multiple changes:
* Ensures that the PBVH exists prior to doing a raycast or other cursor
related actions
* Removes the checks against the PBVH type in `SculptSession` in
favor of debug asserts to avoid crashes and assist in finding other
situations where the state of the PBVH is ambiguous.
Pull Request: https://projects.blender.org/blender/blender/pulls/126953
c2aa9ac9cf