Until now we merged kernel updates even if no hardened versions were
available yet. On one hand we don't want to delay patch-level updates,
on the other hand users of hardened kernels have frequent breakage now[1].
This change aims to provide a solution this issue:
* The hardened patchset now references the kernel version it's released
for (including a sha256 hash for the fixed-output path of the source
tarball).
* The `hardenedKernelFor`-function doesn't just append hardened patches
now, but also overrides version & src to match the kernel version the
patch was built & tested for.
Refs #140281
[1] https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.linuxPackages_hardened.kernel.x86_64-linux/all
(cherry picked from commit bb5aa0109b6db98a2e0a7ba88f5e0287e2374384)
f47c57802e