Add extra overload for to_netcdf

[jenshnielsen]

The current signature does not match with pyright if a non-literal bool is passed.

This fixes type checking of code like this:

import xarray as xr

def myfunc(compute: bool) -> None:
    ds = xr.Dataset()
    ds.to_netcdf(path="myfile.nc",
                compute=compute)

with pyright.

See microsoft/pyright#6069 for context.

[headtr1ck]

There are still some Mypy errors. Maybe my comment fixed them, maybe not, maybe it creates new problems.

Also, feel free to add an entry in whats-new!

[headtr1ck]

I took the liberty to fix the open problems.
Good to go now!

On a side note, maybe I will open an issue over at mypy to request the feature that Union[Literal[True], Literal[False]] == bool

[headtr1ck]

On a side note, maybe I will open an issue over at mypy to request the feature that Union[Literal[True], Literal[False]] == bool

Already exists: python/mypy#14764

[headtr1ck]

Thanks!

[jenshnielsen]

@headtr1ck thanks for finishing this. Sorry for dropping the ball on it