Fix incorrect comment label in partial property snippet

[Copilot]

The FieldProperty code snippet had duplicate // Defining declaration comments, where the second occurrence should have been // Implementing declaration.

• Program.cs (line 182): Changed // Defining declaration → // Implementing declaration on the class containing the property implementation (get => field; set;)

// in file1.cs
public partial class PropertyBag
{
    // Defining declaration        ✅ unchanged
    public partial int MyProperty { get; set; }
}

// In file2.cs
public partial class PropertyBag
{
    // Implementing declaration    ✅ was "Defining declaration"
    public partial int MyProperty { get => field; set; }
}

Labels now match the article's terminology ("defining and implementing member declaration").

[BillWagner]

This LGTM and is ready for final review.

[Copilot]

Pull request overview

This PR fixes a mislabeled comment in the C# “partial property” (<FieldProperty>) snippet so that the two partial declarations are correctly described as defining vs implementing declarations, aligning the snippet’s terminology with the associated article.

Changes:

• Updated the comment in the second partial PropertyBag declaration from // Defining declaration to // Implementing declaration.