* Python: Foundry: make response tool sanitizer internal, drop TOOLBOXES warning
sanitize_foundry_response_tool runs on every tool passed to the Foundry
Responses API, so its @experimental(TOOLBOXES) decorator was emitting a
[TOOLBOXES] ExperimentalWarning for any FoundryChatClient call, even when
no toolbox was involved. The function isn't in __all__ and has no external
callers. Rename to _sanitize_foundry_response_tool and drop the decorator;
the actual toolbox-facing public helpers remain gated.
* Python: Foundry: silence pyright on intentional cross-module private import