[release/5.0] Notify Reference Tracker runtime of disconnect at the right time#58412

Anipik merged 3 commits intodotnet:release/5.0dotnet/runtime:release/5.0from

AaronRobinsonMSFT:reftracker_disconnect_semanticAaronRobinsonMSFT/runtime:reftracker_disconnect_semanticCopy head branch name to clipboard