www/py-httpcore: Update to 0.13.6

Changes:	https://github.com/encode/httpcore/releases

www/py-httpcore/Makefile

 # Created by: Po-Chuan Hsieh <sunpoet@FreeBSD.org>
 
 PORTNAME=	httpcore
-PORTVERSION=	0.13.4
+PORTVERSION=	0.13.6
 CATEGORIES=	www python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}

www/py-httpcore/distinfo

-TIMESTAMP = 1622214126
-SHA256 (httpcore-0.13.4.tar.gz) = 9fa4c623bb9d2280c009c34658cc6315e4fd425a395145645bee205d827263e4
-SIZE (httpcore-0.13.4.tar.gz) = 45139
+TIMESTAMP = 1624189771
+SHA256 (httpcore-0.13.6.tar.gz) = b0d16f0012ec88d8cc848f5a55f8a03158405f4bca02ee49bc4ca2c1fda49f3e
+SIZE (httpcore-0.13.6.tar.gz) = 45278