Fix Ruff lint failure in Gate D whole-stage driver

[Copilot]

The Lint (ruff) GitHub Actions job failed on an F401 violation in scripts/gate_d_whole_stage.py. This PR removes the unused import causing the failure so the lint job can pass.

• Lint failure root cause

  • Removed an unused uuid import from the Gate D whole-stage takeover script.

• Code change

  • File updated: scripts/gate_d_whole_stage.py
  • No behavior or interface changes; this is a cleanup-only fix for the CI lint gate.

import os
import subprocess
import sys
import time
from pathlib import Path