Blender Git Loki

UI: hide object instancing panel for object types that dont support instancing

Basically, only meshes, empties and pointclouds support direct
instancing atm., no need to have the panel for other types.

note: prior to rB2eca054e14b1, collection instancing was possible on all
types (but that was removed in said commit)

note2: for empties, rna_Object_instance_type_itemf should also be
tweaked so we dont get "Vertices" and "Faces" options, but that can be
done in a separate commit

Maniphest Tasks: T88443

Differential Revision: https://developer.blender.org/D11348