ty: check assert_never

Had to bump `ty`, because 0.0.61 added support for `value in [A, B, C]` pattern for type narrowing.

pyproject.toml

@@ -111,7 +111,6 @@ no-matching-overload = "ignore"
 not-subscriptable = "ignore"
 unsupported-dynamic-base = "ignore"
 unsupported-operator = "ignore"
-type-assertion-failure = "ignore"
 
 [tool.ty.environment]
 extra-paths = [

requirements-tools.txt

@@ -1,5 +1,5 @@
 black==26.3.1
 ruff==0.15.12
 poethepoet
-ty==0.0.59
+ty==0.0.61
 gersemi==0.26.1

src/bonsai/bonsai/tool/pset.py

@@ -124,6 +124,9 @@ class Pset(bonsai.core.tool.Pset):
             return bpy.context.scene.GroupPsetProperties
         elif obj_type == "Zone":
             return bpy.context.scene.ZonePsetProperties
+        elif obj_type == "Cost":
+            # No psets for cost items currently.
+            assert False, obj_type
         assert_never(obj_type)
 
     @classmethod