Simplify language model registry + only emit change events on change (#29086)

* Now only does default fallback logic in the registry

* Only emits change events when there is actually a change

Release Notes:

- N/A
d88b06a5dcMichael Sloan committed on 4/19/2025, 8:26:42 AM· committed by GitHubparent98ceffe
5 files changedLine totals unavailable