The auto suggestion editor has required validation even when there is no required attribute on the model

Steps to reproduce

1. Add the following class to the project.

[ServiceConfiguration(typeof(ISelectionQuery))]
public class MyCustomItemQuery : ISelectionQuery
{
    private readonly SelectItem[] _items;

    public MyCustomItemQuery()
    {
        _items = new[]
        {
            new SelectItem { Text = "OneTwoThree", Value = "123" },
            new SelectItem { Text = "TwoThreeFour", Value = "234" }
        };
    }

    public IEnumerable<ISelectItem> GetItems(string query)
    {
        return _items.Where(i => i.Text.StartsWith(query));
    }

    public ISelectItem GetItemByValue(string value)
    {
        return _items.FirstOrDefault(i => i.Value.Equals(value));
    }
}


2. Add the following property and attribute to a page content type.

[AutoSuggestSelection(typeof(MyCustomItemQuery))]
public virtual string TestProperty { get; set; }


3. Create a page of that content type
4. Go to all properties mode
5. Give the test property focus
6. Remove focus from the test property

Observed: The property displays a required validation error.
Expected: No validation error since the property is not marked as required on the model.