Environment details

• OS: Ubuntu 20.04.6 LTS
• Python version: 3.11.7
• pip version: 23.3.1
• google-auth version: 2.26.2

Steps to reproduce

1. Install google-auth
2. Import google.oauth2.id_token module

Hi folks,
it looks like google.oauth2.id_token has an import time dependency of google.auth.transport.requests
https://github.com/googleapis/google-auth-library-python/blob/main/google/oauth2/id_token.py#L65

which requires a requests package
https://github.com/googleapis/google-auth-library-python/blob/main/google/auth/transport/requests.py#L25

that's not defined as a google-auth dependency.
https://github.com/googleapis/google-auth-library-python/blob/main/setup.py#L22

The call to google.auth.transport.requests is only made once in https://github.com/googleapis/google-auth-library-python/blob/main/google/oauth2/id_token.py#L285 so the possible solution will be to move the import to runtime.