Currently it is easy to track newly created debug sessions in an extension but it is not possible to track when a session ends.

things to consider:

• we need a session ID for this because VS Code supports concurrent sessions
• we should not only solve the "debugSessionEnds" problem but broaden the solution for all kind of debug session related events (e.g. loadedScript events from the DA).
• probably related: Extension API - How to determine debug state #10077