update to go1.21.7

go1.21.7 (released 2024-02-06) includes fixes to the compiler, the go command,
the runtime, and the crypto/x509 package. See the Go 1.21.7 milestone on our
issue tracker for details:

- https://github.com/golang/go/issues?q=milestone%3AGo1.21.7+label%3ACherryPickApproved
- full diff: golang/go@go1.21.6...go1.21.7

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

common.mk

@@ -17,7 +17,7 @@ CHOWN:=docker run --rm -v $(CURDIR):/v -w /v alpine chown
 DEFAULT_PRODUCT_LICENSE:=Community Engine
 PACKAGER_NAME?=
 DOCKER_GITCOMMIT:=abcdefg
-GO_VERSION:=1.21.6
+GO_VERSION:=1.21.7
 PLATFORM=Docker Engine - Community
 SHELL:=/bin/bash
 VERSION?=0.0.1-dev