Calling Dispose() on custom IPersistentJobQueue

On server stopping Hangfire may call Dispose() if implementation of IPersistentJobQueue has IDisposable interface.
Sometimes it makes sense, e.g. when IPersistentJobQueue implementation keeps open connection and should close it right on Hangfire server stopping instead of waiting until GC kicks in.

Locate the IPersistentJobQueue interface and the Hangfire server-stopping path first. Check how queue implementations are managed during shutdown, then verify the requested behavior with the existing test structure if available: an implementation that also implements IDisposable should be disposed when the server stops, while other implementations should continue to work.

Written by the indexing model from the issue text.