Fix CommentNotificationEventListenerTest caused by Iteration Order No…

[LucaDai]

Fix Flakiness of CommentNotificationEventListenerTest caused by Iteration Order Nondeterminism

Context

This test was failing nondeterministically due to iteration order differences in user lists.
It passed in some runs but failed in others, depending on whether "john" or "mary" appeared first.
Error Message:

[ERROR] Failures: 
[ERROR]   CommentNotificationEventListenerTest.testNotificationOnCommentAddedWithRawBody:184 expected:<...ment to [[UserImpl:'[mary'], [UserImpl:'john]']] with body simple...> but was:<...ment to [[UserImpl:'[john'], [UserImpl:'mary]']] with body simple...>
[INFO] 
[ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0

Fix

Replaced strict equality (isEqualTo) with a regex match (matches), allowing the order of "john" and "mary" to vary.

[UserImpl:'(mary|john)'], \\[UserImpl:'(john|mary)']]

This change makes the test verify the correctness of the notification content with nondeterministic ordering.

Verification

• Re-ran the suite multiple times with randomized test order → 0 failures observed.
• Confirmed both possible user orderings are accepted by the regex.

Checklist

• Root cause explained in PR
• Fix applied deterministically
• Random-order reruns are green