`disconnect` request does not terminate the adapter process when running standalone

[FlavienVolant]

Describe the bug
When running vscode-js-debug as a standalone DAP adapter (outside of vscode), the adapter remains alive after successfully handling a disconnect request.

According to the Debug Adapter Protocol specification:
The disconnect request asks the debug adapter to disconnect from the debuggee (thus ending the debug session) and then to shut down itself (the debug adapter).

I'm not sure whether this is an intentional choice or a bug.

To Reproduce
Steps to reproduce the behavior:

1. Start vscode-js-debug: node dapDebugServer.js PORT.
2. Establish a debug session.
3. Send disconnect request.
4. Wait for the successful response.
5. The connection is closed but the adapter remains alive.

Additional context
I use my own DAP client.
The same disconnect workflow causes the adapter to exit when using the Java Debug Adapter and debugpy-adapter for Python, which is why I expected the same behavior from vscode-js-debug.

Could you clarify whether this behavior is intentional when running the adapter in standalone ?