build: set min build version to Go 1.22.6

Go 1.23 was released this week, so with this PR we update the build
system to officially support the last two releases.

Dockerfile

@@ -3,7 +3,7 @@
 # /make/builder.Dockerfile
 # /.github/workflows/main.yml
 # /.github/workflows/release.yml
-FROM golang:1.22.5-alpine as builder
+FROM golang:1.22.6-alpine as builder
 
 # Force Go to use the cgo based DNS resolver. This is required to ensure DNS
 # queries required to connect to linked containers succeed.