Unify doc-strings (remove type/rtype)

As this information is already provided in type hints and we don't need to maintain it in two places.

src/ifcopenshell-python/ifcopenshell/api/style/assign_material_style.py

@@ -38,22 +38,17 @@ def assign_material_style(
     to materials. This API function provides that capability.
 
     :param material: The IfcMaterial which you want to assign the style to.
-    :type material: ifcopenshell.entity_instance
     :param style: The IfcPresentationStyle (typically IfcSurfaceStyle) that
         you want to assign to the material. This will then be applied to all
         objects that have that material.
-    :type style: ifcopenshell.entity_instance
     :param context: The IfcGeometricRepresentationSubContext at which this
         style should be used. Typically this is the Model BODY context.
-    :type context: ifcopenshell.entity_instance
     :param should_use_presentation_style_assignment: This is a technical
         detail to accomodate a bug in Revit. This should always be left as
         the default of False, unless you are finding that colours aren't
         showing up in Revit. In that case, set it to True, but keep in mind
         that this is no longer a valid IFC. Blame Autodesk.
-    :type should_use_presentation_style_assignment: bool
     :return: None
-    :rtype: None
 
     Example: