The error in your log is:
Setting up shim-signed (1.34.9+13-0ubuntu2) ...
Installing for x86_64-efi platform.
Could not delete variable: Interrupted system call
grub-install: error: efibootmgr failed to register the boot entry: Block device required.
dpkg: error processing package shim-signed (--configure):
installed shim-signed package post-installation script subprocess returned error exit status 1
The error in your log is: 13-0ubuntu2) ...
Setting up shim-signed (1.34.9+
Installing for x86_64-efi platform.
Could not delete variable: Interrupted system call
grub-install: error: efibootmgr failed to register the boot entry: Block device required.
dpkg: error processing package shim-signed (--configure):
installed shim-signed package post-installation script subprocess returned error exit status 1
It appears that there is a problem with your firmware that prevents shim from uploading the bootloader configuration variables. Is it possible that you are affected by https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/1734147 ?