More ruff linter fixes

core/config.py

@@ -1,6 +1,7 @@
 import importlib
 import logging
 import os
+import sys
 
 import yaml
 
@@ -11,7 +12,7 @@ if not os.path.isfile("config.yml"):
     logger.error(
         "Your config file is missing. Ensure you have copied config-example.yml to config.yml and updated it according to your needs."
     )
-    exit()
+    sys.exit()
 
 # Load config
 with open("config.yml") as f: