Cannot update due to "shim-signed"

[Idiot Annon]

Hello i tried to fix this problem with the help of AI assistant on the main site but it could not help so now im asking you guys. 
Whenever im trying to run sudo apt upgrade or sudo apt dist-upgrade I get the same error and i have no idea what to do with it. 

Code:

sudo apt upgrade
Reading package lists...
Building dependency tree...
Reading state information...
Calculating upgrade...
The following package was automatically installed and is no longer required:
  linux-headers-5.15.0-122
Use 'sudo apt autoremove' to remove it.
The following packages have been kept back:
  compiz grub-efi-amd64-bin grub-efi-amd64-signed libb-hooks-op-check-perl
  libclass-xsaccessor-perl libemail-address-xs-perl libnetaddr-ip-perl
  libparams-classify-perl libperlio-gzip-perl libsocket6-perl
  libsub-identify-perl libtext-levenshteinxs-perl libtime-moment-perl
  libvariable-magic-perl
0 upgraded, 0 newly installed, 0 to remove and 14 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] Setting up shim-signed (1.51.4+15.8-0ubuntu1) ...
/var/lib/dpkg/info/shim-signed.postinst: 165: /usr/lib/grub/grub-multi-install: not found
dpkg: error processing package shim-signed (--configure):
installed shim-signed package post-installation script subprocess returned error exit status 127
Errors were encountered while processing:
shim-signed

What i got from doing my research so far is that shim-signed is something to do with Secure Boot UEFI option and i was suggested to go to the BIOS and turn of Secure Boot. My motherboard on this machine is quite old and it doesnt have Secure Boot option in the BIOS. Also im not using any other OS on this machine, no dual boot stuff or anything, just Linux Lite. 
AI suggested a few different commands to run such as "sudo apt --fix-broken install" but every thing it told me to try just gave me the same error.

[stevef]

What do these commands show ?

Code:

ls -l /usr/lib/grub

Code:

file /usr/lib/grub/grub-multi-install

[Idiot Annon]

What do these commands show ?

Code:

ls -l /usr/lib/grub

Code:

file /usr/lib/grub/grub-multi-install

Here's the output:

Code:

 linuxlite  ~  ls -l /usr/lib/grub
total 80
lrwxrwxrwx 1 root root    34 sie  1  2022 grub-mkconfig_lib -> ../../share/grub/grub-mkconfig_lib
drwxr-xr-x 2 root root 36864 maj 14  2023 i386-pc
drwxr-xr-x 3 root root 36864 maj 12  2023 x86_64-efi
drwxr-xr-x 2 root root  4096 maj 12  2023 x86_64-efi-signed

Code:

 linuxlite  ~  file /usr/lib/grub/grub-multi-install
/usr/lib/grub/grub-multi-install: cannot open `/usr/lib/grub/grub-multi-install' (No such file or directory)

[stevef]

It appears that your system is missing a  script (named grub-multi-install) which is called by the shim-signed upgrade process.  As the script is missing, the upgrade process crashes.  The script location is part of the protected system area that isn't usually touched so while it may be possible just to copy the script back to the system, we really need to understand why the script isn't where it should be.

Other things may be wrong as well and the AI advised attempts may have had adverse effects.

Are you aware of anything just before the problem started that may have affected your system files ?
Do you have a System Restore Utility (aka Timeshift) snapshot taken before the problem started ?
Would you be prepared to back up your data and re-install the system ?