devel/py-gapic-generator: Update to 1.3.0

Changes:	https://github.com/googleapis/gapic-generator-python/releases

devel/py-gapic-generator/Makefile

 PORTNAME=	gapic-generator
-PORTVERSION=	1.2.0
+PORTVERSION=	1.3.0
 CATEGORIES=	devel python
 MASTER_SITES=	CHEESESHOP
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}

devel/py-gapic-generator/distinfo

-TIMESTAMP = 1661599243
-SHA256 (gapic-generator-1.2.0.tar.gz) = 0d4b448c6f6d52b74dbc3a74108842ac78e19a3b649fe6d059dffc4958616541
-SIZE (gapic-generator-1.2.0.tar.gz) = 607203
+TIMESTAMP = 1662558034
+SHA256 (gapic-generator-1.3.0.tar.gz) = 37630383ad16b0ffd29abd8e2e1712a9626563545551bfb11b64f6ed1af9d0df
+SIZE (gapic-generator-1.3.0.tar.gz) = 613321