No longer able to enable state overlay

I'm no longer able to set `/opt` writable on my image. It worked several weeks ago

```dockerfile
FROM quay.io/bootc-devel/fedora-bootc-43-standard

RUN echo "password" | passwd --stdin
RUN rm -rf /opt && mkdir /opt
RUN systemctl enable ostree-state-overlay@opt.service
```

```
systemctl status ostree-state-overlay@opt.service
� ostree-state-overlay@opt.service - OSTree State Overlay On /opt
Loaded: loaded (/usr/lib/systemd/system/ostree-state-overlay@.service; enabled; preset: disabled)
Drop-In: /usr/lib/systemd/system/service.d
\u2514\u250010-timeout-abort.conf
/etc/systemd/system/ostree-state-overlay@opt.service.d
\u2514\u2500override.conf
Active: failed (Result: exit-code) since Fri 2026-01-16 16:34:36 CET; 59min left
Invocation: 3583bbc39a514d5cba9efdd3e0b6dd24
Docs: man:ostree(1)
Process: 798 ExecStart=/usr/bin/ostree admin state-overlay opt /opt (code=exited, status=1/FAILURE)
Main PID: 798 (code=exited, status=1/FAILURE)
Mem peak: 2.3M
CPU: 14ms

janv. 16 16:34:36 fedora ostree[798]: error: mount(/opt): Argument invalide
janv. 16 16:34:36 fedora systemd[1]: Starting ostree-state-overlay@opt.service - OSTree State Overlay On /opt...
janv. 16 16:34:36 fedora systemd[1]: ostree-state-overlay@opt.service: Main process exited, code=exited, status=1/FAILURE
janv. 16 16:34:36 fedora systemd[1]: ostree-state-overlay@opt.service: Failed with result 'exit-code'.
janv. 16 16:34:36 fedora systemd[1]: Failed to start ostree-state-overlay@opt.service - OSTree State Overlay On /opt.

```