Cosmos: NullReferenceException when projecting out a collection of owned entity types

[roji]

This is another bug in a series of issues related to projecting out owned types in various ways (#31696, #34067):

_ = await context.Employee
    .Select(x => x.User.Emails)
    .SingleAsync();

Repro

await using var context = new CosmosDbContext();
await context.Database.EnsureDeletedAsync();
await context.Database.EnsureCreatedAsync();

context.Employee.Add(new()
{
    id = "1",
    User = new()
    {
        Name = "John",
        Emails = [
            new() { EmailAdress = "[email protected]", Type = "A"},
            new() { EmailAdress = "[email protected]", Type = "B"}
        ]
    }
});
await context.SaveChangesAsync();

context.ChangeTracker.Clear();

_ = await context.Employee
    .Select(x => x.User.Emails)
    .SingleAsync();

public class CosmosDbContext : DbContext
{
    public DbSet<RootObject> Employee { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseCosmos(
                "https://192.168.64.6:8081",
                "C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==",
                "Test",
                o => o.HttpClientFactory(() => new HttpClient(
                        new HttpClientHandler
                        {
                            ServerCertificateCustomValidationCallback =
                                HttpClientHandler.DangerousAcceptAnyServerCertificateValidator
                        }))
                    .ConnectionMode(ConnectionMode.Gateway))
            .UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking)
            .LogTo(Console.WriteLine, LogLevel.Information)
            .EnableSensitiveDataLogging();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<RootObject>().ToContainer("DummyContainer");
        modelBuilder.Entity<RootObject>().HasNoDiscriminator();
    }
}

public class RootObject
{
    public string id { get; set; }
    public User User { get; set; }
    public string _rid { get; set; }
    public string _self { get; set; }
    public string _etag { get; set; }
    public string _attachments { get; set; }
    public int _ts { get; set; }
}

public class User
{
    public string Name { get; set; }
    public ICollection<Emails> Emails { get; set; }
}

public class Emails
{
    public string EmailAdress { get; set; }
    public string Type { get; set; }
}

public class EmployeeDTO
{
    public string Id { get; set; }
    public string Name { get; set; }
    public ICollection<Emails> Emails { get; set; }
}