Swoole build bug on gnu-docker

[crazywhalecc]

https://github.com/static-php/static-php-cli-hosted/actions/runs/22979862291/job/66717031332#step:10:29406

[henderkes]

I'll be so glad to drop EL7 support. EL8 still has pain points though, as does Debian Bullseye. I'm not sure if it's realistic to jump right up to el9/bookworm, though.

[crazywhalecc]

I think we just drop iouring support for swoole when building on gnu docker since gnu docker will be soon deprecated.