The [ExportToolButton] attribute is used to create clickable buttons in the inspector so,
the property must be a Callable that will be executed when clicking the button.
To fix a violation of this rule, change the type of the property to Callable.
Alternatively, if you intended to export a normal property, replace the
[ExportToolButton] attribute with [Export].
Do not suppress a warning from this rule. The exported property must be a Callable
so it can executed in the editor when clicking the button in the inspector.