*: git.monogon.dev -> source.monogon.dev

This implements T882, setting our (virtual) GOPATH to source.monogon.dev
for this repository.

Test Plan: Refactor, CI only.

X-Origin-Diff: phab/D686
GitOrigin-RevId: c5e2309089948ffc3a98e68e2e0e1cbb157d3a36
diff --git a/metropolis/test/e2e/kubernetes_helpers.go b/metropolis/test/e2e/kubernetes_helpers.go
index fffbd1b..b3dceae 100644
--- a/metropolis/test/e2e/kubernetes_helpers.go
+++ b/metropolis/test/e2e/kubernetes_helpers.go
@@ -30,7 +30,7 @@
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/tools/clientcmd"
 
-	apb "git.monogon.dev/source/nexantic.git/metropolis/proto/api"
+	apb "source.monogon.dev/metropolis/proto/api"
 )
 
 // GetKubeClientSet gets a Kubeconfig from the debug API and creates a K8s ClientSet using it. The identity used has