Arch Linux

/usr/sbin/init can no longer be run in a container with systemd 253 (systemd-253-1). Can be reproduced with podman as follows:

Create a `Dockerfile`:
```
FROM archlinux:latest
RUN pacman -Syu --noconfirm # so you actually get systemd 253
CMD /usr/sbin/init
```
Build and run with podman:
```
podman build -t archlinux-253 .
podman run --rm -it archlinux-253
```
This will die with:
```
Failed to fork: Operation not permitted
[!!!!!!] Failed to start up manager.
Exiting PID 1...
```
This can also be reproduced with Docker, but since systemd doesn't really work well with Docker doing this is a lot more complicated. Instructions can be found in https://github.com/moby/moby/issues/45042.

Reported upstream in https://github.com/systemd/systemd/issues/26474. It has already been fixed upstream in https://github.com/systemd/systemd/commit/a2275dcb9d48925f8192f44ec371710ce812bfce.

I set Severity to High since this "only" prevents an up-to-date Arch to be used in containers when systemd's `/usr/sbin/init` is the main process, but it does not affect regular systems.