chore(test): remove duplicate imports in demo pipeline tests

Clean duplicate import declarations to reduce noise and keep test maintenance focused without changing assertions or runtime behavior.

tests/demo/test_pipeline.py

@@ -14,19 +14,6 @@ import torch
 
 from opengait.demo.sconet_demo import ScoNetDemo
 
-import json
-import pickle
-from pathlib import Path
-import subprocess
-import sys
-import time
-from typing import Final, cast
-
-import pytest
-import torch
-
-from opengait.demo.sconet_demo import ScoNetDemo
-
 REPO_ROOT: Final[Path] = Path(__file__).resolve().parents[2]
 SAMPLE_VIDEO_PATH: Final[Path] = REPO_ROOT / "assets" / "sample.mp4"
 CHECKPOINT_PATH: Final[Path] = REPO_ROOT / "ckpt" / "ScoNet-20000.pt"