devel/py-xarray: Update to 0.20.1

Changes:	https://github.com/pydata/xarray/releases
		https://github.com/pydata/xarray/blob/main/doc/whats-new.rst#whats-new

devel/py-xarray/Makefile

 # Created by: Po-Chuan Hsieh <sunpoet@FreeBSD.org>
 
 PORTNAME=	xarray
-PORTVERSION=	0.20.0
+PORTVERSION=	0.20.1
 CATEGORIES=	devel python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}

devel/py-xarray/distinfo

-TIMESTAMP = 1636117278
-SHA256 (xarray-0.20.0.tar.gz) = 8ea93274868f78c46332fc3b75f4628f6d99e59a0315e294a99397ad1eb777a5
-SIZE (xarray-0.20.0.tar.gz) = 2896515
+TIMESTAMP = 1637072998
+SHA256 (xarray-0.20.1.tar.gz) = 9c0bffd8b55fdef277f8f6c817153eb51fa4e58653a7ad92eaed9984164b7bdb
+SIZE (xarray-0.20.1.tar.gz) = 2896122