If you know your way around apt and pinning a bit you could use the debian bullseye repository for updates until the PureOS repository is fixed. In my post I quoted most of my configuration. But please be aware: this is not something officially supported by Purism and I do not have the time to support you in case it doesn’t work as you expected.
If you do it right there should more or less be a dozen packages being updated from bullseye updates.