httpx OAuth2 client has incorrect oauth_error_class

[axonxorz]

Describe the bug

OAuth2Client of the httpx integration incorrectly sets oauth_error_class as OAuthError, despite the superclass authlib.oauth2.client.OAuth2Client configuring it as OAuth2Error

To Reproduce

from authlib.integrations.httpx_client import OAuth2Client
from authlib.integrations.base_client import OAuthError
from authlib.oauth2 import OAuth2Error

class MyClient(OAuth2Client):
    pass

assert MyClient.oauth_error_class is OAuthError
assert MyClient.oauth_error_class is OAuth2Error  # AssertionError

Expected behavior

OAuth2Client.oauth_error_class = OAuth2Error

Environment:

• OS: Linux 6.5.12-100.fc37.x86_64 SMP PREEMPT_DYNAMIC Mon Nov 20 22:28:44 UTC 2023 x86_64
• Python Version: Linux 6.5.12-100.fc37.x86_64 SMP PREEMPT_DYNAMIC Mon Nov 20 22:28:44 UTC 2023 x86_64
• Authlib Version: 1.3.0