No boot, and error messages after kernel update

The 5.13 kernel is indeed long EOL, and thus unavailable, as well as the driver headers for it. Your issue is similar to many before you that got their drivers removed by updating while keeping that kernel.

You should chroot and:

  • remove the kernel 5.13
  • install the kernel 5.10 LTS, 5.15 LTS and/or newer supported
  • install the drivers
sudo mhwd-kernel -r linux513
sudo mhwd-kernel -i linux515
sudo mhwd -a pci nonfree 0300