Update docstring of @validate_quantities with checks_on_return → validations_on_return #2788
Description
In the docstring for @validate_quantities, some of the examples provide an argument to the checks_on_return parameter. We changed that at some point to be validations_on_return. We should change checks_on_return → validations_on_return in that docstring, and make sure it's not used in other places too.