regression: 7.0.0 breaks registering process subreaper on Apple silicon Description of problem: When running any container on the QEMU virtual guest that is using a utility like `tini` which is trying to register itself as a process subreaper I get an error message like this: ``` [FATAL tini (1)] PR_SET_CHILD_SUBREAPER is unavailable on this platform. Are you using Linux >= 3.4? ``` The issue has been observed by multiple people on Apple silicon Macs, e.g. in these issues: https://github.com/docker/for-mac/issues/6620#issuecomment-1694380189 https://github.com/GoogleCloudPlatform/spark-on-k8s-operator/issues/1735 Steps to reproduce: 1. Install QEMU 7.0.0+ on an Apple silicon MAC 2. Run a virtual guest 3. Try to register a process subreaper, e.g. like `tini -s` does Additional information: the issue was introduced in QEMU 7.0.0 with this commit: https://gitlab.com/qemu-project/qemu/-/commit/220717a6f46a99031a5b1af964bbf4dec1310440 tini readme talking about process subreaping: https://github.com/krallin/tini#subreaping