test: pre-fetch CLI tools

As `_out` is a shared volume across Drone steps, we should prefetch CLI
dependencies early, as fetching them concurrently from multiple steps
might lead to surpising results.

Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>

.drone.jsonnet

@@ -133,7 +133,7 @@ local setup_ci = {
 
   commands: [
     'setup-ci',
-    'make ./_out/kubectl',
+    'make ./_out/kubectl ./_out/kubestr ./_out/clusterctl',
   ],
   environment: {
     "BUILDKIT_FLAVOR": "cross",