fix: minor type hint in interpreter_in_ctx

[IthacaDream]

Fix minor type hint in interpreter_in_ctx

Summary

• Correct return annotation from Interpreter to AsyncIterator[Interpreter] for the @asynccontextmanager method.
• Aligns with actual usage (async with ...), resolves type-checker noise, no runtime impact

Before	After

[IthacaDream]

This is staled.