devel/py-immutables: Update to 0.20

- Convert to USE_PYTHON=pep517

Changes:	https://github.com/MagicStack/immutables/releases

devel/py-immutables/Makefile

 PORTNAME=	immutables
-PORTVERSION=	0.19
+PORTVERSION=	0.20
 CATEGORIES=	devel python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
@@ -12,8 +12,11 @@ LICENSE=	APACHE20 MIT
 LICENSE_COMB=	multi
 LICENSE_FILE_APACHE20=	${WRKSRC}/LICENSE-APACHE
 
+BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}setuptools>=42:devel/py-setuptools@${PY_FLAVOR} \
+		${PYTHON_PKGNAMEPREFIX}wheel>=0:devel/py-wheel@${PY_FLAVOR}
+
 USES=		python
-USE_PYTHON=	autoplist concurrent distutils
+USE_PYTHON=	autoplist concurrent pep517
 
 post-install:
 	${FIND} ${STAGEDIR}${PYTHON_SITELIBDIR} -name '*.so' -exec ${STRIP_CMD} {} +

devel/py-immutables/distinfo

-TIMESTAMP = 1663672828
-SHA256 (immutables-0.19.tar.gz) = df17942d60e8080835fcc5245aa6928ef4c1ed567570ec019185798195048dcf
-SIZE (immutables-0.19.tar.gz) = 85490
+TIMESTAMP = 1692211731
+SHA256 (immutables-0.20.tar.gz) = 1d2f83e6a6a8455466cd97b9a90e2b4f7864648616dfa6b19d18f49badac3876
+SIZE (immutables-0.20.tar.gz) = 88933