Remove manual bindings for arange (#81380)
The functional variant of one of the `arange` overloads has a schema mismatch with the out variant. The functional one has `Scalar step`, but the corresponding out variant has `Scalar step=1`. This isn't allowed, so it had to be special-cased in the python codegen and manually bound. This adds the default `step` value to the functional overload and removes the special-casing.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81380
Approved by: https://github.com/ngimel
