godot_dart/0.8.0

• Fix casting to builtin types from Variant.
• BREAKING: Remove bindingToken as a paremeter of type info. Simplified instance binding creation which should also lower the extension's memory usage.
• BREAKING: Remove GodotObject.cast<T> as Dart downcasting now works. Replaced with GodotObject.as<T>. This extension may be removed entirely in future versions.