databases/py-psycopg-c: Update to 3.1.18

Changes:	https://github.com/psycopg/psycopg/blob/master/docs/news.rst
		https://www.psycopg.org/psycopg3/docs/news.html

databases/py-psycopg-c/Makefile

 PORTNAME=	psycopg-c
-PORTVERSION=	3.1.16
+PORTVERSION=	3.1.18
 CATEGORIES=	databases python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}

databases/py-psycopg-c/distinfo

-TIMESTAMP = 1703227852
-SHA256 (psycopg-c-3.1.16.tar.gz) = 24f9805e0c20742c72c7be1412e3a600de0980104ff1a264a49333996e6adba3
-SIZE (psycopg-c-3.1.16.tar.gz) = 561407
+TIMESTAMP = 1708449102
+SHA256 (psycopg-c-3.1.18.tar.gz) = ffff0c4a9c0e0b7aadb1acb7b61eb8f886365dd8ef00120ce14676235846ba73
+SIZE (psycopg-c-3.1.18.tar.gz) = 561356