LibGit2SharpException: could not find appropriate mechanism for credentials

Reproduction steps

Upgraded from v0.26.2 to v0.30.0, had compilation issues. Fair enough, we were quite out of date.
We changed the credentials provider as this was now located in the FetchOptions (see #2065).
I even tried setting the ProxyOptions.ProxyType to None as that was now Auto by default.

Has there anything changed regarding credentials between those versions? I didn't immediately spotted something on the releases/changes page.

Expected behavior

Everything keeps working as normal.

Actual behavior

Exception is thrown when trying to clone a repository:
LibGit2Sharp.LibGit2SharpException: could not find appropriate mechanism for credentials at LibGit2Sharp.Core.Ensure.HandleError(Int32 result) in /_/LibGit2Sharp/Core/Ensure.cs:line 136 at LibGit2Sharp.Core.Proxy.git_clone(String url, String workdir, GitCloneOptions& opts) in /_/LibGit2Sharp/Core/Proxy.cs:line 278 at LibGit2Sharp.Repository.Clone(String sourceUrl, String workdirPath, CloneOptions options) in /_/LibGit2Sharp/Repository.cs:line 810

Version of LibGit2Sharp (release number or SHA1)

v0.30.0

Operating system(s) tested; .NET runtime tested

Windows 11
.NET Framework 4.8

Reproduce the clone failure on Windows 11 with LibGit2Sharp v0.30.0 and compare the credential setup with v0.26.2, starting from CloneOptions, FetchOptions, and ProxyOptions. Inspect the reported paths in Core/Ensure.cs, Core/Proxy.cs, and Repository.cs, then use #2065 and the release changes to establish whether credential behavior changed and what a corrected outcome should be.