Honor disabled timeouts during token refresh

[Shubham-Padkonde]

A client created with timeout=None documents that requests wait without a socket timeout, but refresh_access_token substitutes DEFAULT_TIMEOUT (100 seconds). Applications that explicitly disable timeouts therefore still time out during token refresh.

Pass the client's stored timeout directly to the refresh POST. The constructor already supplies the default when no override is provided. Regression tests cover None and a numeric override.

Validation: the None case fails before the fix; all 102 unit tests pass afterward. Ruff lint and formatting pass.

[ineil-dbx]

Hi @Shubham-Padkonde, I’ve raised this with our engineering team for further review. They’ll be able to review the pull request and address it as appropriate.