update to go1.22.6

- https://github.com/golang/go/issues?q=milestone%3AGo1.22.6+label%3ACherryPickApproved
- full diff: https://github.com/golang/go/compare/go1.22.5...go1.22.6

go1.22.6 (released 2024-08-06) includes fixes to the go command, the compiler,
the linker, the trace command, the covdata command, and the bytes, go/types,
and os/exec packages. See the Go 1.22.6 milestone on our issue tracker for
details.

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

.devcontainer/devcontainer.json

@@ -12,7 +12,7 @@
 	"features": {
 		"ghcr.io/devcontainers/features/docker-in-docker:2": {},
 		"ghcr.io/devcontainers/features/go:1": {
-			"version": "1.21"
+			"version": "1.22.6"
 		}
 	},