Masking cpios from clr-boot-manager doesn't remove them from bootloader entries

[bwarden]

If you want to block installation of the i915 firmware initrd by linking it to /dev/null in /etc/initrd.d, the cpio won't be installed, but the bootloader kernel entries will still refer to it in the kernel command line, causing boot to fail.

We should ensure that the generated kernel bootloader entries do not include initrd= parameters for any files that do not exist in the EFI partition.

Related to #3192