Wow that is news to me. Looks like 5.13 is eol according to this. https://github.com/fabianishere/pve-edge-kernel I will stay on the 5.11 kernel for now.
Thanks
Mind you,this is Ubuntu kernel, so they will backport everything that is needed to be up-to-date. RHEL and Centos have much much older kernels that are backported, so that you have maybe 3.10-1000 or more updates.
This is perfectly okay.