Change null check to type check for Person in ObsoleteGetDataExample

Co-authored-by: adegeo <67293991+adegeo@users.noreply.github.com>

Author: Copilot

dotnet-desktop-guide/winforms/migration/snippets/clipboard-dataobject-net10/net/csharp/ObsoletePatterns.cs

@@ -32,9 +32,8 @@ public static void ObsoleteGetDataExample()
             object data = Clipboard.GetData("MyApp.Person");  // Obsolete method
 
             // Returns a NotSupportedException instance for a custom object type
-            if (data != null)
+            if (data is Person person)
             {
-                Person person = (Person)data;
                 Console.WriteLine($"Processing person: {person.Name}, Age: {person.Age}");
             }
         }

dotnet-desktop-guide/winforms/migration/snippets/clipboard-dataobject-net10/net/vb/ObsoletePatterns.vb

@@ -27,7 +27,7 @@ Namespace ClipboardExamples
             Dim data As Object = Clipboard.GetData("MyApp.Person")  ' Obsolete method
 
             ' Returns a NotSupportedException instance for a custom object type
-            If data IsNot Nothing Then
+            If TypeOf data Is Person Then
                 Dim person As Person = CType(data, Person)
                 Console.WriteLine($"Processing person: {person.Name}, Age: {person.Age}")
             End If