ENG-10533 - Public API timeout importing 99 CSV users

Description

Looks like this started happening after we made ENG-8883

Steps to reproduce:

1. Download attached file with new users/groups

2. Import it via Public API (BASE_URL/api/public/bulk-user-import/)

*ACTUAL RESULT:* Waiting for couple minutes and request still not ended in postman. In Sentry we have this:

*EXPECTED RESULT:* Request successfully imported in reasonable amount of time.

NOTE: I tried same file but only with 30 records and requested ended in 3.75s.