Potential fix for pull request finding 'Unused import'

Co-authored-by: Copilot Autofix powered by AI <223894421+github-code-quality[bot]@users.noreply.github.com>

Author: Tw1ZZLER

sequence/utils/metrics/builtins.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from .event_types import EventTypes, register_event_type
+from .event_types import EventTypes
 from .metric_types import (
     CounterMetric,
     DeliveryTimeMetric,