Enable BPF/cgroup based firewalling
systemd complains:
Jan 05 03:38:40 pureos systemd[1]: File /lib/systemd/system/systemd-journald.service:12 configures an IP firewall (IPAddressDeny=any), but the local system does not support BPF/cgroup based firewalling.
Jan 05 03:38:40 pureos systemd[1]: Proceeding WITHOUT firewalling in effect! (This warning is only shown for the first loaded unit using IP firewalling.)