Revert feat(normalization): add validation for empty features in NormalizerProcessorStep and UnnormalizerProcessorStep (#2087)

Revert "feat(normalization): add validation for empty features in NormalizerProcessorStep and UnnormalizerProcessorStep (#2087)"

This reverts commit f173265354.

tests/policies/test_policies.py

@@ -234,6 +234,7 @@ def test_act_backbone_lr():
     assert cfg.policy.optimizer_lr_backbone == 0.001
 
     dataset = make_dataset(cfg)
+    preprocessor, _ = make_pre_post_processors(cfg.policy, None)
     policy = make_policy(cfg.policy, ds_meta=dataset.meta)
     optimizer, _ = make_optimizer_and_scheduler(cfg, policy)
     assert len(optimizer.param_groups) == 2

tests/processor/test_normalize_processor.py

@@ -534,18 +534,6 @@ def test_empty_observation():
     assert result == transition
 
 
-def test_empty_features_raises_error():
-    """Test that empty features dict raises ValueError."""
-    norm_map = {FeatureType.VISUAL: NormalizationMode.MEAN_STD}
-    stats = {OBS_IMAGE: {"mean": [0.5], "std": [0.2]}}
-
-    with pytest.raises(ValueError, match="Normalization features cannot be empty"):
-        NormalizerProcessorStep(features={}, norm_map=norm_map, stats=stats)
-
-    with pytest.raises(ValueError, match="Normalization features cannot be empty"):
-        UnnormalizerProcessorStep(features={}, norm_map=norm_map, stats=stats)
-
-
 def test_empty_stats():
     features = {OBS_IMAGE: PolicyFeature(FeatureType.VISUAL, (3, 96, 96))}
     norm_map = {FeatureType.VISUAL: NormalizationMode.MEAN_STD}