This would be another workaround yes. The workarounds all have in common, that they shouldn't be seen as permanent solution but temporary workarounds until an update on Proxmox LXC stack solves the issue for now (1). Luckily according to the bug ticket ( https://bugzilla.proxmox.com/show_bug.cgi?id=7006 ) the patch is already included in a new lxc package and pushed as update to the test-repository. So if you want to try that out you could enable the test-repository. Since you will also get everything else (since with the test-repo you are *guess what* a beta tester) this might not be what you want. But at some point the new packages in test also get pushed to no-subscription depending on how much new issues for an updated package are reported. Since the change and potential effects are quite limited for the fix I would expect that it won't take very long in this case.
(1) As already said: This is neither the first time nor will be the last time that an update will break docker in lxcs. So if you don't have a really good reason (like that want to use the iGPU but the app can only be installed as docker like immich) to run a docker container in a lxc you should consider moving your docker workloads to one docker-vm. In theory an update can break stuff in a vm too. But in fact this happens very rarely and is usually a lot easier to fix. One example: The last docker update changed the default minimum API version which broke portainer. But that issue can be worked around in one minute with a simple config file change see https://github.com/portainer/portainer/issues/12925#issuecomment-3516549977 for details). And if you happen to not use the docker upstream packages but the one provided by Debian or Ubuntu you still use an older version so no problem with that. In fact most packages on stable or LTS distributions might be a little bit old but usually won't "surpise" one with breaking changes
