feat(sdk-py): add sentinel to skip auto loading api key on sdk client create (#6500)

**Description:** There are times a user might want to create the client,
but conditionally set the API key. For example, consider a complex auth
situation where the system has user callers using jwts and system
callers using API keys. This allows explicitly disabling the
auto-loading behavior of API keys in the client today, so no key is set.
**Issue:** N/A
**Dependencies:** None
**Twitter handle:** N/A

.github/scripts/check_sdk_methods.py

@@ -38,7 +38,7 @@ def main():
         tree = ast.parse(file.read())
 
     classes = find_classes(tree)
-  
+
     def is_sync(class_spec: Tuple[str, List[str]]) -> bool:
         return class_spec[0].startswith("Sync")