Fix hang on Ctrl+C when tiering is enabled (#16719)

Fix hang on Ctrl+C when tiering is enabled (#16719)

Fix hang on Ctrl+C when tiering is enabled

- When the work thread count is nonzero at the time of Ctrl+C, by the time `TieredCompilationManager::Shutdown(BOOL)` runs (during `DllMain` for process detach), the background worker thread has already been torn down abruptly and it does not get a chance to exit gracefully and set the event, and Shutdown() hangs the process waiting for the event forever.
- It looks like there is no benefit to waiting for the work to complete, fixed by removing the wait and the event
- In the MusicStore benchmark it looks like the arch folder was missing in the 'publish' folder path. In case there is a difference in bin directory layout between the CI dotnet and current dotnet, changed to check for both paths.