SA1135 doesn't fire when using file-scoped namespace syntax

[zizhengtai]

• C# 10
• .NET 6
• StyleCop 1.2.0-beta.354

When a project uses the root project namespace My.Project, and has the following sub-namespaces:

• My.Project.Foo
• My.Project.Bar

SA1135 works as expected when using the old namespace syntax:

namespace My.Project.Bar
{
    using Foo;  // <-- not fully qualified, triggers SA1135
}

However, it doesn't fire when using the new file-scoped namespace syntax:

namespace My.Project.Bar;

using Foo;  // <-- doesn't trigger SA1135