feat: allow k8s to skip destroy

We skip destroying for LXD we should do the same for k8s. This way
we can see if it's working or not. Once the removal and cleanup
epic is done, this should be put back to false. For now skip it.

.github/workflows/smoke.yml

@@ -101,4 +101,7 @@ jobs:
         cd tests
         export MODEL_ARCH=$(go env GOARCH)
 
+        # Skip destroy to keep the environment up.
+        export SKIP_DESTROY=true
+
         sg snap_microk8s './main.sh -c microk8s -v smoke_k8s'