[MINOR] test: Fix ConcurrentModifiedException while use TestAppender

[maobaolong]

What changes were proposed in this pull request?

Fix ConcurrentModifiedException while use TestAppender

Why are the changes needed?

[ERROR] testNewAppWhileCheckLeak{ExtensionContext}  Time elapsed: 0.3 s  <<< ERROR!
java.util.ConcurrentModificationException
    at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:911)
    at java.util.ArrayList$Itr.next(ArrayList.java:861)
    at org.apache.uniffle.common.log.TestLoggerExtension$TestAppender.wasLogged(TestLoggerExtension.java:106)
    at org.apache.uniffle.common.log.TestLoggerExtension.wasLogged(TestLoggerExtension.java:73)
    at org.apache.uniffle.server.storage.LocalStorageManagerTest.testNewAppWhileCheckLeak(LocalStorageManagerTest.java:399)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)

Does this PR introduce any user-facing change?

No.

How was this patch tested?

Existing UTs.

[jerqi]

Could you commit this to branch-0.10, too?

[github-actions]

Test Results

 2 966 files  +23   2 966 suites  +23   6h 28m 16s ⏱️ + 9m 18s
 1 096 tests ± 0   1 094 ✅ + 1   2 💤 ±0  0 ❌  - 1 
13 735 runs  +53  13 705 ✅ +54  30 💤 ±0  0 ❌  - 1 

Results for commit 2e0ffda. ± Comparison against base commit 0552d3b.

[maobaolong]

#2286 @jerqi Here it is.