math/py-cdecimal: deprecate and mark BROKEN with Python 3.9

Note: upstream does not support it after Python-3.2, and a fast C
implementation of the decimal module (_decimal) is bundled with Python.

PR:		261870

math/py-cdecimal/Makefile

@@ -13,10 +13,19 @@ COMMENT=	Fast drop-in replacement for the Decimal module
 LICENSE=	BSD2CLAUSE
 LICENSE_FILE=	${WRKSRC}/LICENSE.txt
 
+DEPRECATED=	upstream does not support it after Python-3.2
+
 USES=		python:3.6-3.8
 USE_PYTHON=	distutils autoplist
 
+.include <bsd.port.pre.mk>
+
+.if ${PYTHON_VER} == 3.9
+# Note: a fast C implementation of the decimal module (_decimal) is bundled with Python
+BROKEN=	no member named 'tp_print' in 'struct _typeobject'
+.endif
+
 post-install:
 	@${STRIP_CMD} ${STAGEDIR}${PYTHONPREFIX_SITELIBDIR}/cdecimal*.so
 
-.include <bsd.port.mk>
+.include <bsd.port.post.mk>