Merge release/3.0.1 to master

Merge branch 'release/3.0.0'

Remove JobbrServer from DI container

Create the one instance manually, otherwise the WebHostBuilder might
create a new instance for every sub-component, causing multiple calls to
WireUp and thus multiple subscriptions on the MessageDispatcher

Fix JobbrServer DI registration

Use transient life style for MessageDispatcher

Align dependencies in the nuspec file

Align Microsoft dependency versions around .NET 6

Fixed unit test

Remove targetFramework group from nuspec

Update Microsoft.Extensions.Logging.Abstractions to 7.0.0