Ok so I removed the fake nfs mount line, and I just force snapd to start after autofs.
$ mkdir /lib/systemd/system/snapd.service.d
$ cat << EOF > /lib/systemd/system/snapd.service.d/snapd-after-autofs.conf
[Unit]
After=snapd.socket autofs.service
EOF
$ reboot
-- Boot 2c7259846bbb47239ac7c5ece1093132 --
sept. 23 08:21:00 si22 systemd[1]: Starting Snap Daemon...
sept. 23 08:21:00 si22 snapd[959]: AppArmor status: apparmor is enabled and all features are available
sept. 23 08:21:09 si22 snapd[959]: AppArmor status: apparmor is enabled and all features are available
sept. 23 08:21:10 si22 snapd[959]: overlord.go:263: Acquiring state lock file
sept. 23 08:21:10 si22 snapd[959]: overlord.go:268: Acquired state lock file
sept. 23 08:21:10 si22 snapd[959]: daemon.go:247: started snapd/2.57.1 (series 16; classic) ubuntu/22.04 (amd64) li>
sept. 23 08:21:10 si22 snapd[959]: daemon.go:340: adjusting startup timeout by 1m35s (pessimistic estimate of 30s p>
sept. 23 08:21:10 si22 snapd[959]: backend.go:135: snapd enabled NFS support, additional implicit network permissio>
sept. 23 08:21:10 si22 systemd[1]: Started Snap Daemon.