Fix mypy errors

Author: hramezani

pydantic_settings/sources/base.py

@@ -426,7 +426,7 @@ class Settings(BaseSettings):
                 values[name] = value
                 continue
 
-            if _lenient_issubclass(sub_model_field.annotation, BaseModel) and isinstance(value, dict):
+            if sub_model_field is not None and _lenient_issubclass(sub_model_field.annotation, BaseModel) and isinstance(value, dict):
                 values[field_key] = self._replace_field_names_case_insensitively(sub_model_field, value)
             else:
                 values[field_key] = value

pydantic_settings/sources/providers/cli.py

@@ -594,7 +594,7 @@ def parse_args_insensitive_method(
                     if matched:
                         arg = matched.group(1).lower() + matched.group(2)
                     insensitive_args.append(arg)
-                return parser_method(root_parser, insensitive_args, namespace)  # type: ignore
+                return parser_method(root_parser, insensitive_args, namespace)
 
             return parse_args_insensitive_method