Wiping hard disks with DBAN requires to disconnect all other hard drives you do not intend to wipe. More importantly, you cannot use your PC for other tasks since it needs to boot the DBAN OS.
Luckily, Hyper-V allows you to passthrough raw disks. This even works on Windows 10 or 11 if you install the Hyper-V role.
You can use DBAN or Shredos. Mount the ISO file as bootable device in the VM and wipe away!
resize partition in gParted
make sure not to delete and recreate any partition because this changes the UUID of the partition which is referenced in fstab and /etc/initramfs-tools/conf.d/resume
reboot machine
at grub prompt
ls to list disks
ls (hd1,gpt2)/ to search for /boot/grub or /grub partition (try different partitions)
when found use following commands with correct partition: