BUG: medfix nanwarn doesn't do anything

[andykee]

Describe the issue:

Doctoring says:

nanwarn : bool, optional
        If True, a RuntimeWarning will be raised if NaNs are present
        in the output. Default is False.

The nanwarn argument is never used in the function though.

Reproduce the code example:

n/a

Error message:

No response

Runtime information:

1.0.0
1.24.4
1.10.1
3.10.12 | packaged by conda-forge | (main, Jun 23 2023, 22:41:52) [Clang 15.0.7 ]