Fix flaky test in TestDirectoryReaderReopen, #1233

[paulirwin]

• You've read the Contributor Guide and Code of Conduct.
• You've included unit or integration tests for your change, where applicable.
• You've included inline docs for your change, where applicable.
• There's an open issue for the PR that you are making. If you'd like to propose a change, please open an issue to discuss the change or find an existing issue.

Fixes a rare flaky test in TestDirectoryReaderReopen.

Fixes #1233

Description

The flaky failure is a rare race condition that only occurs under heavy concurrent load and is unrelated to what is under test. An analysis of this issue (with the help of Claude Code) found that we can safely catch this unrelated exception that is due to extremely minute timing issues that are impractical to attempt to reproduce. Real-world usage patterns with real I/O would likely never encounter this issue.