PHP will not work without interruption when PHP_LSAPI_CHILDREN is not set

According to [this document](https://docs.litespeedtech.com/lsws/cp/cpanel/long-run-script/), I configured everything on the development server (ubuntu) and the production server (linux).

But the production server was working properly and the development server was not.
Finally I found a small configuration difference between the two servers.
I had not set `PHP_LSAPI_CHILDREN` on the development server.
After setting `PHP_LSAPI_CHILDREN`, everything worked.

Start with the linked long-run script documentation and review how PHP_LSAPI_CHILDREN is described for development and production servers. Confirm whether the reported interruption is expected when the variable is unset; done should include a documented or verified configuration requirement.

Written by the indexing model from the issue text.