databases/py-sqlalchemy20: Update to 2.0.15

Changes:	https://docs.sqlalchemy.org/en/20/changelog/changelog_20.html

databases/py-sqlalchemy20/Makefile

 PORTNAME=	sqlalchemy
-PORTVERSION=	2.0.13
+PORTVERSION=	2.0.15
 CATEGORIES=	databases python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}

databases/py-sqlalchemy20/distinfo

-TIMESTAMP = 1684104368
-SHA256 (SQLAlchemy-2.0.13.tar.gz) = 8d97b37b4e60073c38bcf94e289e3be09ef9be870de88d163f16e08f2b9ded1a
-SIZE (SQLAlchemy-2.0.13.tar.gz) = 9286442
+TIMESTAMP = 1685162102
+SHA256 (SQLAlchemy-2.0.15.tar.gz) = 2e940a8659ef870ae10e0d9e2a6d5aaddf0ff6e91f7d0d7732afc9e8c4be9bbc
+SIZE (SQLAlchemy-2.0.15.tar.gz) = 9296612