Add init kwargs extra attribs.

Author: kschwab

pydantic_settings/sources.py

@@ -389,13 +389,15 @@ def __init__(
         nested_model_default_partial_update: bool | None = None,
     ):
         self.init_kwargs = {}
-        init_kwargs_names = set(init_kwargs.keys())
+        init_kwarg_names = set(init_kwargs.keys())
         for field_name, field_info in settings_cls.model_fields.items():
             alias_names, *_ = _get_alias_names(field_name, field_info)
-            init_kwarg_name = init_kwargs_names & set(alias_names)
+            init_kwarg_name = init_kwarg_names & set(alias_names)
             if init_kwarg_name:
                 preferred_alias = alias_names[0]
+                init_kwarg_names -= init_kwarg_name
                 self.init_kwargs[preferred_alias] = init_kwargs[init_kwarg_name.pop()]
+        self.init_kwargs.update({key: val for key, val in init_kwargs.items() if key in init_kwarg_names})
 
         super().__init__(settings_cls)
         self.nested_model_default_partial_update = (