Keeping *internal* API and ABI compatibility makes working with an already
complex codebase more mentally demanding than it needs to be.
Remember: plugins should be in-tree and upstream! If your out of tree plugin
stops working then it should be upstream.
The public-facing libfwupd will remain API and ABI stable for obvious reasons.
The end year is legally and functionally redundant, and more importantly causes
cherry-pick conflicts when trying to maintain old branches. Use git for history.
