by this doc:
https://en.opensuse.org/SDB:Encrypted_root_file_system#Additional_steps_when_using_hibernation_with_encrypted_swap_partition

> [werwolf@workbook] ~
> ❯ cat /etc/dracut.conf.d/99-resume.conf
> add_device+=" UUID=ffb2ef5d-0757-49b6-987f-9166f4528318 "
> add_dracutmodules+=" resume "
> 
> [werwolf@workbook] ~
> ❯ cat /etc/dracut.conf.d/99-luks-key.conf
> install_items+=" /etc/main.key "
> 
> [werwolf@workbook] ~
> ❯ sudo cat /etc/crypttab | grep swap
> [sudo] пароль для root:
> cr_swap  UUID=ffb2ef5d-0757-49b6-987f-9166f4528318  /etc/main.key  key-slot=1,discard
> 
> [werwolf@workbook] ~
> ❯ cat /etc/fstab | grep swap
> /dev/mapper/cr_swap                             swap               swap   discard                       0  0
> 
> [werwolf@workbook] ~
> ❯ free
>                total        used        free      shared  buff/cache   available
> Mem:        15128532     3875824     9142956      178356     2604596    11252708
> Swap:       17761600           0    17761600
> 
> [werwolf@workbook] ~
> ❯ cat /proc/cmdline
> BOOT_IMAGE=/boot/vmlinuz-6.6.11-1-default root=UUID=eb54b167-a9a2-4641-8b74-b645cb0e4776 splash=silent resume=UUID=ffb2ef5d-0757-49b6-987f-9166f4528318 quiet security=apparmor mitigations=off delayacct
> 
> [werwolf@workbook] ~
> ❯ sudo systemctl hibernate
> Call to Hibernate failed: Not enough swap space for hibernation
> 


I remember that it worked before, it definitely worked on my previous laptop.
Because of this problem, I temporarily had to abandon encrypted swap since I
need hibernation. and this is unsafe.