DEPR: deprecate pytz support #46463
Description
We've already agreed on changing the defaults from pytz to stdlib/zoneinfo objects in 2.0. I'm now thinking we should go even further and deprecate support for pytz objects altogether. We wouldn't necessarily have to raise, but do something like
def disallow_pytz(tzinfo tz):
if is_pytz_tzinfo(tz):
return corresponding_zoneinfo(tz)
return tz
The upshot of this is that we could remove a bunch of cython code that is pytz-specific. From there we would be able to de-duplicate conversion._localize_tso with tzconversion.tz_convert_from_utc_single.