devel/py-protobuf: Update to 5.29.1

Changes:	https://github.com/protocolbuffers/protobuf/releases

devel/py-protobuf/Makefile

 PORTNAME=	protobuf
-PORTVERSION=	5.28.3
+PORTVERSION=	5.29.1
 PORTEPOCH=	1
 CATEGORIES=	devel python
 MASTER_SITES=	PYPI

devel/py-protobuf/distinfo

-TIMESTAMP = 1729927001
-SHA256 (protobuf-5.28.3.tar.gz) = 64badbc49180a5e401f373f9ce7ab1d18b63f7dd4a9cdc43c92b9f0b481cef7b
-SIZE (protobuf-5.28.3.tar.gz) = 422479
+TIMESTAMP = 1734888260
+SHA256 (protobuf-5.29.1.tar.gz) = 683be02ca21a6ffe80db6dd02c0b5b2892322c59ca57fd6c872d652cb80549cb
+SIZE (protobuf-5.29.1.tar.gz) = 424965