Reproducible failure in TestNRTThreads.testNRTThreads

### Description

```
org.apache.lucene.index.TestNRTThreads > testNRTThreads FAILED
java.io.IOException: MockDirectoryWrapper: file "_3.cfs" is still open: cannot delete
at __randomizedtesting.SeedInfo.seed([1B9ED508F7DABC16:8047C113B621AA7D]:0)
at org.apache.lucene.tests.store.MockDirectoryWrapper.deleteFile(MockDirectoryWrapper.java:640)
at org.apache.lucene.store.LockValidatingDirectoryWrapper.deleteFile(LockValidatingDirectoryWrapper.java:37)
at org.apache.lucene.util.FileDeleter.delete(FileDeleter.java:234)
at org.apache.lucene.util.FileDeleter.delete(FileDeleter.java:227)
at org.apache.lucene.util.FileDeleter.decRef(FileDeleter.java:109)
at org.apache.lucene.index.IndexFileDeleter.decRef(IndexFileDeleter.java:631)
at org.apache.lucene.index.IndexFileDeleter.checkpoint(IndexFileDeleter.java:589)
at org.apache.lucene.index.IndexWriter.rollbackInternalNoCommit(IndexWriter.java:2534)
at org.apache.lucene.index.IndexWriter.rollbackInternal(IndexWriter.java:2453)
at org.apache.lucene.index.IndexWriter.rollback(IndexWriter.java:2445)
at org.apache.lucene.index.IndexWriter.close(IndexWriter.java:1368)
```

```
./gradlew :lucene:core:test --tests "org.apache.lucene.index.TestNRTThreads.testNRTThreads" -Ptests.seed=1B9ED508F7DABC16 -Ptests.nightly=true
```

### Gradle command to reproduce

_No response_

Start by rerunning org.apache.lucene.index.TestNRTThreads.testNRTThreads with the supplied Gradle command and seed. Trace the open _3.cfs file through MockDirectoryWrapper, FileDeleter, IndexFileDeleter, and IndexWriter rollback/close. Done means the seeded test completes without the file-still-open IOException.

Written by the indexing model from the issue text.