devel/py-mox3: Deprecate/Set to expire

* Upstream is no longer active and the repository has been archived [1].
  There are also no consumers left in the tree so deprecate the port
  and set an expiration date.

[1] https://lists.openstack.org/pipermail/openstack-discuss/2020-June/015518.html

devel/py-mox3/Makefile

@@ -11,6 +11,9 @@ WWW=		https://docs.openstack.org/mox3/
 LICENSE=	APACHE20
 LICENSE_FILE=	${WRKSRC}/COPYING.txt
 
+DEPRECATED=	Upstream no longer active and repository has been archived. See also: https://lists.openstack.org/pipermail/openstack-discuss/2020-June/015518.html
+EXPIRATION_DATE=2024-03-31
+
 BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pbr>=2.0.0:devel/py-pbr@${PY_FLAVOR}
 RUN_DEPENDS=	${PYTHON_PKGNAMEPREFIX}pbr>=2.0.0:devel/py-pbr@${PY_FLAVOR} \
 		${PYTHON_PKGNAMEPREFIX}fixtures>=3.0.0:devel/py-fixtures@${PY_FLAVOR}