EL9: strange cgroup-related error

On a freshly installed EL9 system, I get the following error when starting `cdp-listend`:

```
Mar 28 11:10:11 psonar1.ijclab.in2p3.fr systemd[1]: cdp-listend.service: Failed to set 'io.weight' attribute on '/system.slice/cdp-listend.service' to 'default 100': No such file or directory
```

It doesn't seem to prevent `cdp-listend` to work...