Credential handling in 0.27.0-preview-0096 fails against VSTS/Azure

Between versions preview-0034 and preview-0096 the credential handling changed and no longer works with VSTS/Azure

Include="LibGit2Sharp" Version="0.27.0-preview-0034" - works correctly

Include="LibGit2Sharp" Version="0.27.0-preview-0096" - authentication fails

Reproduction steps

string surl = "https://testsite.visualstudio.com/testsite/_git/Test";
string un = "pat";
string pwd = "";

var credentialsProvider = new CredentialsHandler((_url, _user, _cred) =>
new UsernamePasswordCredentials
{
Username = un,
Password = pwd
}
);

var references = Repository.ListRemoteReferences(surl, credentialsProvider);

Expected behavior

Should return references

Actual behavior

preview-0096 throws "this remote has never connected" error when authentication fails.

Version of LibGit2Sharp (release number or SHA1)

0.27.0-preview-0096

Operating system(s) tested; .NET runtime tested

OSx, .net core 5.0

Inizia riproducendo il problema con LibGit2Sharp 0.27.0-preview-0034 e preview-0096 usando Repository.ListRemoteReferences, l'URL VSTS/Azure e il CredentialsHandler fornito. Confronta la gestione delle credenziali tra le due versioni; il lavoro è completato quando il caso preview-0096 esegue correttamente l'autenticazione e restituisce i riferimenti invece di generare "this remote has never connected".