Repair startup failure from prohibited system calls.

```
type=SECCOMP msg=audit(1701717734.613:2217): auid=4294967295 uid=472 gid=468 ses=4294967295 subj=mtail (enforce) pid=26617 comm="mtail" exe="/usr/sbin/mtail" sig=31 arch=c000003e syscall=160 compat=0 ip=0x564d954b636e code=0x80000000
```

Adjusting the deny list was attempted, but not successful.
Instead, replace the deny- with an allow-list.