nonpython example now repr all exceptions

The definition of `repr_failure` on the `YamlItem` subclass only handled the custom `YamlException` class, which hides all other errors from the user. By adding in the `super` call we ensure all other exception types also appropriately handled by `repr_failure`.

doc/en/example/nonpython/conftest.py

@@ -38,6 +38,7 @@ class YamlItem(pytest.Item):
                     "   no further details known at this point.",
                 ]
             )
+        return super().repr_failure(excinfo)
 
     def reportinfo(self):
         return self.path, 0, f"usecase: {self.name}"