[php-src] Issue #8282: oops, unknown child exited with code 0

Issue: https://github.com/php/php-src/issues/8282 Comment Author: derekrprice Actually, it's not exactly an incompatibility.  Without changing the container, moving from k8s 1.19 to 1.20 caused php-fpm's /status endpoint to begin intermittently taking longer.  The previous 2s timeout on the healthcheck was hit more frequently and k8s killed the container.  I think the "Oops, unknown child" warnings had to do with k8s killing some health check processes before they completed. There is still an issue here, I think, since performance was impacted as of k8s 1.20 with no other changes, but I think the issue is more likely with Kubernetes than with PHP FPM.