Relax restriction on ConditionalAttribute when attributed to local methods.

[HobbsCode]

Local methods attributed with Conditional("DEBUG") are currently required to be static. If the local method only captures 'this', then it is the equivalent of an instance method and should be treated like an instance method. The restriction should be relaxed to permit local methods that only capture 'this'. Code like the following would then become valid.

public class Person 
{
    private string? m_Name;
    
    public string? Name 
    { 
        get => m_Name;
        
        set 
        {
            m_Name = value;
        
            Print();
        
            return;
        
            [Conditional("DEBUG")] // If the restriction is relaxed, then this is allowed.
            void Print() => Console.WriteLine($"The name is {Name}.");
        }
    }  
    
}