improvement(plugins): debug log manifest dump (#4997)

Before this we were printing all the manifests we were applying at the
verbose level which imo is too low a level and can make the logs very
noisy.

Noticed this e.g. when streaming logs via the dashboard.

core/src/plugins/kubernetes/kubectl.ts

@@ -111,7 +111,7 @@ export async function apply({
 
   const input = Buffer.from(encodeYamlMulti(manifests))
 
-  log.verbose(`Applying Kubernetes manifests:\n${input.toString()}`)
+  log.debug(`Applying Kubernetes manifests:\n${input.toString()}`)
 
   let args = ["apply"]
   dryRun && args.push("--dry-run")