audio/py-gtts: Make build system PEP-518 conform

 Declare minimum build dependencies for build system
 See: https://peps.python.org/pep-0518/#build-system-table

PR:		268902
Reported by:	Charlie Li <vishwin@freebsd.org>

audio/py-gtts/Makefile

@@ -1,5 +1,6 @@
 PORTNAME=	gTTS
 DISTVERSION=	2.3.0
+PORTREVISION=	1
 CATEGORIES=	audio python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
@@ -11,7 +12,8 @@ WWW=		https://github.com/pndurette/gTTS
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
-BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}wheel>0:devel/py-wheel@${PY_FLAVOR}
+BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}setuptools>0:devel/py-setuptools@${PY_FLAVOR} \
+		${PYTHON_PKGNAMEPREFIX}wheel>0:devel/py-wheel@${PY_FLAVOR}
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}click>=8.1.3:devel/py-click@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}requests>=2.28.0:www/py-requests@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}six>=1.16.0:devel/py-six@${PY_FLAVOR}