#10047 fix: Fix race condition in `get_user_config_service` singleton Pull request opened by edgarrmondragon Description Multiple threads could simultaneously pass the

_user_config_service is not None

check and each create a new instance after acquiring the lock. Add the same guard inside the lock (double-checked locking). Checklist • I have read the contribution guide Was generative AI tooling used to co-author this PR? • Yes (please specify the tool below) Related Issues • Closes #XXXX Summary by Sourcery Bug Fixes: • Prevent multiple threads from creating separate UserConfigService instances by adding a double-checked guard inside the lock in get_user_config_service. meltano/meltano