Git HTTP Auth breaks w/1.14

Upgrading to 1.14.0, and cloning via HTTP auth (username + password) gives this stack trace:

  File "/opt/conda/lib/python3.10/site-packages/pygit2/remotes.py", line 171, in ls_remotes
    self.connect(callbacks=callbacks, proxy=proxy)
  File "/opt/conda/lib/python3.10/site-packages/pygit2/remotes.py", line 120, in connect
    payload.check_error(err)
  File "/opt/conda/lib/python3.10/site-packages/pygit2/callbacks.py", line 93, in check_error
    raise self._stored_exception
  File "/opt/conda/lib/python3.10/site-packages/pygit2/callbacks.py", line 416, in wrapper
    return f(*args)
  File "/opt/conda/lib/python3.10/site-packages/pygit2/callbacks.py", line 484, in _credentials_cb
    ccred = get_credentials(credentials, url, username, allowed)
  File "/opt/conda/lib/python3.10/site-packages/pygit2/callbacks.py", line 569, in get_credentials
    creds = fn(url_str, username_str, allowed)
  File "/opt/conda/lib/python3.10/site-packages/scmrepo/git/backend/pygit2/callbacks.py", line 51, in credentials
    from pygit2.credentials import GIT_CREDENTIAL_USERPASS_PLAINTEXT, UserPass
ImportError: cannot import name 'GIT_CREDENTIAL_USERPASS_PLAINTEXT' from 'pygit2.credentials' (/opt/conda/lib/python3.10/site-packages/pygit2/credentials.py)

Version 1.13.3 works fine though :).

Thanks.

首先比较 pygit2 1.13.3 和 1.14.0 的 credentials API，重点关注 scmrepo/git/backend/pygit2/callbacks.py 中的 import。使用用户名和密码复现一次 HTTP clone，然后验证使用 pygit2 1.14.0 时身份验证能够正常工作，且不会出现报告中的 ImportError。