[Flaky Test] TestInputManager_Create/does_not_start_an_input_with_duplicated_ID/non-empty_ID

## Flaky Test

* **Test Name:** TestInputManager_Create/does_not_start_an_input_with_duplicated_ID/non-empty_ID
* **Branch:** main
* **Artifact Link:** https://github.com/elastic/beats/actions/runs/33015284659/job/98331810092?pr=52791
* **Notes** This failure was in the MacOS tests so potentially is a timing problem from the MacOS runner.

### Stack Trace

```
=== Failed
=== FAIL: filebeat/input/filestream/internal/input-logfile TestInputManager_Create/does_not_start_an_input_with_duplicated_ID/non-empty_ID (0.00s)
manager_test.go:281:
Error Trace: /Users/runner/work/beats/beats/filebeat/input/filestream/internal/input-logfile/manager_test.go:281
Error: "{\"level\":\"debug\",\"ts\":1787779716.168968,\"logger\":\"filestream.store_cache\",\"msg\":\"initializing filestream shared store cache entry\",\"input_type\":\"\",\"filestream_store_key\":\"test:0x1f10b5c2d580\"}\n{\"level\":\"debug\",\"ts\":1787779716.168971,\"logger\":\"filestream.store_cache\",\"msg\":\"initialized filestream shared store cache entry\",\"input_type\":\"\",\"filestream_store_key\":\"test:0x1f10b5c2d580\",\"store_users_count\":1}\n{\"level\":\"debug\",\"ts\":1787779716.1690052,\"logger\":\"filestream.store_cache\",\"msg\":\"filestream shared store cleaner started\",\"input_type\":\"\",\"filestream_store_key\":\"test:0x1f10b5c2d580\"}\n" does not contain "filestream input ID 'non-empty-ID' is duplicated:"
Test: TestInputManager_Create/does_not_start_an_input_with_duplicated_ID/non-empty_ID

=== FAIL: filebeat/input/filestream/internal/input-logfile TestInputManager_Create/does_not_start_an_input_with_duplicated_ID (0.00s)

=== FAIL: filebeat/input/filestream/internal/input-logfile TestInputManager_Create (0.00s)

DONE 1822 tests, 2 skipped, 3 failures in 35.761s
Error: failed to execute go: exit status 1
```

Start with filebeat/input/filestream/internal/input-logfile/manager_test.go at line 281 and the TestInputManager_Create/does_not_start_an_input_with_duplicated_ID/non-empty_ID case. Review the linked MacOS artifact and rerun the focused test to determine why the duplicate-ID log is missing. Done means the test reliably observes the expected duplicate-ID message without weakening its assertion.

Written by the indexing model from the issue text.