Description of the problem, including code/CLI snippet

Current handling for retry_transient_errors does not include any handling of requests.exceptions.Timeout. Requests to gitlab.com do occasionally timeout, but this tends to be a transient issue, it would be nice if through some additional parameter (or perhaps even the same parameter) this could be retried by the Gitlab client.

Expected Behavior

HTTP requests are retried on timeout error.

Actual Behavior

requests.exceptions.Timeout is raised.

Specifications

• python-gitlab version: 4.9.0
• API version you are using (v3/v4): v4
• Gitlab server version (or gitlab.com): gitlab.com