devel/aws-c-common: Update to 0.9.21

ChangeLog:
	https://github.com/awslabs/aws-c-common/releases/tag/v0.9.21
	https://github.com/awslabs/aws-c-common/releases/tag/v0.9.20

devel/aws-c-common/Makefile

 PORTNAME=	aws-c-common
 DISTVERSIONPREFIX=	v
-DISTVERSION=	0.9.19
+DISTVERSION=	0.9.21
 PORTEPOCH=	1
 CATEGORIES=	devel
 

devel/aws-c-common/distinfo

-TIMESTAMP = 1715421032
-SHA256 (awslabs-aws-c-common-v0.9.19_GH0.tar.gz) = 196430fda1bca2c77df7d9199232956d371a92f49ee48fd6c29ff969410ca0ed
-SIZE (awslabs-aws-c-common-v0.9.19_GH0.tar.gz) = 555937
+TIMESTAMP = 1717846086
+SHA256 (awslabs-aws-c-common-v0.9.21_GH0.tar.gz) = e831adaa2d203218e627b3b43e30bcb628a480618f42f86f585a172839234e68
+SIZE (awslabs-aws-c-common-v0.9.21_GH0.tar.gz) = 556353