revert(config): restore use_imagenet_stats default to True

Co-authored-by: Khalil Meftah <s1lent4gnt@users.noreply.github.com>

src/lerobot/configs/default.py

@@ -33,7 +33,7 @@ class DatasetConfig:
     episodes: list[int] | None = None
     image_transforms: ImageTransformsConfig = field(default_factory=ImageTransformsConfig)
     revision: str | None = None
-    use_imagenet_stats: bool = False
+    use_imagenet_stats: bool = True
     video_backend: str = field(default_factory=get_safe_default_codec)
     streaming: bool = True