Fix scalar register_modules skipping config key for optional components

When a scalar value is mis-passed to register_modules (e.g. bool from
legacy positional super().__init__), record (None, None) in config like
the None branch instead of skipping register_to_config entirely. This
keeps config keys aligned with __init__ signature so .components and
enable_model_cpu_offload do not raise ValueError after init succeeds.

Author: cursoragent

src/diffusers/pipelines/pipeline_utils.py

@@ -215,7 +215,7 @@ def register_modules(self, **kwargs):
             elif isinstance(module, (bool, int, float, str)):
                 # Scalar values (e.g. bool mis-passed as image_encoder from legacy super().__init__) are not
                 # model components — skip library tuple registration. See https://github.com/huggingface/diffusers/issues/6969
-                register_dict = {}
+                register_dict = {name: (None, None)}
             else:
                 library, class_name = _fetch_class_library_tuple(module)
                 register_dict = {name: (library, class_name)}