Provide support for `zoneinfo` objects

[scw]

Since Python 3.9, Python has included the zoneinfo module for timezone conversions. Much of the Python ecosystem has moved over to this rather than depending on the somewhat idiosyncratic pytz module. Would it be possible to switch to this built-in library? Some libraries continue to support both with fallbacks to continue supporting older Python versions, for example here is the PR which added zoneinfo support to the babel package.

[bkemper24]

Thanks for the suggestion. I'm looking into this.