perf: avoid slow Docker live lane cleanup

scripts/test-live-cli-backend-docker.sh

@@ -366,10 +366,6 @@ WRAP
   fi
 fi
 tmp_dir="$(mktemp -d)"
-cleanup() {
-  rm -rf "$tmp_dir"
-}
-trap cleanup EXIT
 source /src/scripts/lib/live-docker-stage.sh
 openclaw_live_stage_source_tree "$tmp_dir"
 # Use a writable node_modules overlay in the temp repo. Vite writes bundled