fix: reduce workers count to 5

On some customer deployments there is a really high spike of CPU usage that causes healthcheck failures. Reducing the worker count should reduce the CPU usage and make this less of a problem.
This change is not expected to affect scanning speed and make it slower as most of the time is spent on pulling images.

Author: ivanstanev

config.default.json

@@ -11,7 +11,7 @@
     "MAX_SIZE": 10000,
     "MAX_AGE_MS": 60000
   },
-  "WORKERS_COUNT": 10,
+  "WORKERS_COUNT": 5,
   "REQUEST_QUEUE_LENGTH": 2,
   "QUEUE_LENGTH_LOG_FREQUENCY_MINUTES": 15,
   "INTEGRATION_ID": "",