Filer - Investigate and fix the issue causing filer CI testing to get stuck

There was a test failed during filer [CI run](https://github.com/bcgov/lear/actions/runs/9602201110/job/26482526035). Though this can be fixed by adding correct format of config env, another issue occurred. [CI testing](https://github.com/bcgov/lear/actions/runs/9603030223/job/26485651876) got stuck for a long time with new error.


Currently, [one test](https://github.com/bcgov/lear/blob/main/queue_services/entity-filer/tests/integration/test_publish_event.py#L28) is skipped so that other part of testing can be verified.

**TODO**
- [ ] investigate the cause of this issue and fix it
- [ ] verify that CI completes within an acceptable time frame

Start with the linked CI runs and queue_services/entity-filer/tests/integration/test_publish_event.py at line 28, where the test is currently skipped. Compare the failing and stuck CI runs to identify the cause, then restore the test and verify that the filer CI completes within an acceptable time frame.

Written by the indexing model from the issue text.