lisa.trace: Fix MissingTraceEventError invocations
Ensure it is always called with either a TraceEventCheckerBase or an iterable of strings, that are then combined with AndTraceEventChecker.
GitLab Maintenance scheduled for Thursday, 18th December 2025, from 7:00 AM to 10:00 AM BST. GitLab will be in read-only mode and experience short periods of complete downtime (up to 20 minutes) during this window.
Ensure it is always called with either a TraceEventCheckerBase or an iterable of strings, that are then combined with AndTraceEventChecker.