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/bonsai/bonsai/tool/blender.py

@@ -785,7 +785,6 @@ class Blender(bonsai.core.tool.Blender):
             to False, which will make datablock deletion significantly faster
             by avoiding unnecessary Blender data checks.
         :return: None
-        :rtype: None
         """
         collection_name = repr(data_block).split(".", 2)[-1].split("[", 1)[0]
         getattr(bpy.data, collection_name).remove(
@@ -799,7 +798,6 @@ class Blender(bonsai.core.tool.Blender):
         :param data_blocks: iterable of data blocks to remove
         :param remove_unused_data: set to True to purge data that would be orphaned by the operation
         :return: None
-        :rtype: None
         """
         data_blocks = list(data_blocks)
         if remove_unused_data:

src/bonsai/bonsai/tool/qto.py

@@ -121,7 +121,6 @@ class Qto(bonsai.core.tool.Qto):
         """_summary_: Returns the related cost item and related quantities of the product
 
         :param ifc-instance product: ifc instance
-        :type product: ifcopenshell.entity_instance.entity_instance
 
         :return list of dictionaries in the form [
         {
@@ -132,7 +131,6 @@ class Qto(bonsai.core.tool.Qto):
         "quantity_value" : XX,
         "quantity_type" : XX
         }]
-        :rtype: list
 
         Example: