---
fixes:
  - |
      Fixes `bug 1923528`_, drop ``WorkerService`` class which spawns child
      service proceses with given number ``api_worker`` as a config value.
      Without this fix, it results in that the worker processes, the number of
      them is ``api_worker``, spawn each child processes unintendedly.
      ``api_worker`` is designed just for the number of workers, and not for
      their children.

      .. _bug 1923528 : https://bugs.launchpad.net/tacker/+bug/1923528