Indexing a tree by path yields different result with trailing slash

[mburtka]

When a slash is included when indexing into a tree to a subtree, the resulting TreeEntry has a path with a duplicated last path part.

using System.Text;
using LibGit2Sharp;

var path = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());

using var repo = new Repository(Repository.Init(path, isBare: true));

var bytes = Encoding.UTF8.GetBytes("Hello, World!");

var blob = repo.ObjectDatabase.CreateBlob(new MemoryStream(bytes));

var td = new TreeDefinition();
td.Add("some/deeply/nested/file", blob, Mode.NonExecutableFile);

var tree = repo.ObjectDatabase.CreateTree(td);

var withSlash = tree["some/deeply/"].Path;
var withoutSlash = tree["some/deeply"].Path;

Console.WriteLine(withSlash);       // some/deeply/deeply
Console.WriteLine(withoutSlash);    // some/deeply

I was seeing this across Linux and Windows, on versions 0.31 and 0.32 and .NET 10 and Framework 4.8