Remove config argument from event handlers

For the purpose of migrating to Celery to run event handler inside a
worker, Config object is not serializable. And from the usage of config
argument, every event handler can just access module_build_service.conf
directly. This removal would make the migration easier.

Signed-off-by: Chenxiong Qi <cqi@redhat.com>

tests/test_utils/test_utils.py

@@ -1238,7 +1238,7 @@ class TestBatches:
         # the components just once.
         for msg in further_work:
             if type(msg) == KojiBuildChange:
-                module_build_service.scheduler.handlers.components.complete(conf, msg)
+                module_build_service.scheduler.handlers.components.complete(msg)
 
         # Since we have reused all the components in the batch, there should
         # be fake KojiRepoChange message.