v0.10.8

• Breaking change (serialization): Removed Generic[T] backwards compatibility from SerializableAttrs (announced in v0.9.6).
• Stopped using self.log in Program config load errors as the logger won't be initialized yet.
• Added check to ensure reply fallback removal is only attempted once.
• Fixed remove_event_handler throwing a KeyError if no event handlers had been registered for the specified event type.
• Fixed deserialization showing wrong key names on missing key errors.