Boot repair suggests reinstalling Grub to the MBR of sda pointing to sda1 which is your 14.04 install. I don’t know why unless that is the old Grub you were using. I would have expected it to point to sda6 which was your 20.04 and now shows 22.04 but may not be complete. Your sda7 partition (24.04 attempt?) is corrupted so is not likely to do anything.
You could accept the suggestion of boot repair and install Grub for 14.04 to the MBR and see if you can boot it then run sudo update-grub to see if you get an entry for 20.04 or 22.04 and see if you can boot that. You could also try to chroot into the system on sda6 (22.04) and reinstall/update grub.
As pointed out above, direct upgrade is only available to consecutive LTS versions and in your case going from 20.04 to 22.04 and after that is successful, going from 22.04 to 24.04. You waited until after support for 20.04 ended before trying this which is what led to the problems.