Inspect property descriptor via type __dict__

Accessing an instance property through the class object now intentionally
raises (it must be accessed through an instance), so InstancePropertiesVisibleOnClass
can no longer use GetAttr to retrieve the descriptor. Read it from the
type's __dict__ instead, which bypasses the descriptor protocol.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: jhonabreul

src/embed_tests/Inspect.cs

@@ -26,8 +26,12 @@ public void InstancePropertiesVisibleOnClass()
         {
             var uri = new Uri("http://example.org").ToPython();
             var uriClass = uri.GetPythonType();
-            var property = uriClass.GetAttr(nameof(Uri.AbsoluteUri));
-            var pyProp = (PropertyObject)ManagedType.GetManagedObject(property.Reference);
+            // Accessing an instance property through the class object invokes the
+            // descriptor protocol, which intentionally raises (an instance property
+            // must be accessed through an instance). To inspect the descriptor
+            // itself, read it from the type's __dict__, which bypasses __get__.
+            using var classDict = uriClass.GetAttr("__dict__");
+            var property = classDict.GetItem(nameof(Uri.AbsoluteUri)); var pyProp = (PropertyObject)ManagedType.GetManagedObject(property.Reference);
             Assert.AreEqual(nameof(Uri.AbsoluteUri), pyProp.info.Value.Name);
         }