AsyncCompletion sample does not work

[inequation]

The sample simply does not work in current VS2022.

Repro steps:

1. Get code from this repo.
2. Open AsyncCompletion.sln in Visual Studio 2022 Community 17.14.13.
3. Build the extension in Debug.
4. Set breakpoints in every single method in the extension code, every single property and constructor.
5. Start a debugging session.
6. In the EXP VS2022 instance, click "continue without code" and create a new text file.
7. Observe breakpoints in properties and constructors hitting.
8. Start typing, trying to trigger the element name completion.
9. Observe that none of the breakpoints in the methods hit, not even in the GetOrCreate methods of the providers.

Expected behaviour:

Extension code should execute and register the completion and commit managers.