update Golang to 1.21.3 (#2616)

Author: jdn5126

Makefile

@@ -22,7 +22,7 @@
 # VERSION is the source revision that executables and images are built from.
 VERSION ?= $(shell git describe --tags --always --dirty || echo "unknown")
 # GOLANG_IMAGE is the building golang container image used.
-GOLANG_IMAGE ?= public.ecr.aws/eks-distro-build-tooling/golang:1.20.10-11-gcc-al2
+GOLANG_IMAGE ?= public.ecr.aws/eks-distro-build-tooling/golang:1.21.3-4-gcc-al2
 # BASE_IMAGE_CNI is the base layer image for the primary AWS VPC CNI plugin container
 BASE_IMAGE_CNI ?= public.ecr.aws/eks-distro-build-tooling/eks-distro-minimal-base-iptables:latest.2
 # BASE_IMAGE_CNI_INIT is the base layer image for the AWS VPC CNI init container

go.mod

@@ -1,6 +1,6 @@
 module github.com/aws/amazon-vpc-cni-k8s
 
-go 1.20
+go 1.21
 
 require (
 	github.com/apparentlymart/go-cidr v1.1.0