kernel: Fix infinite recursion between version and patches

[roberth]

Description of changes

Make the kernel version not depend on the patches and such, so that the correct kernel version is available to patch expressions without infinite recursion.

• Closes nixos/kernel: Expose the unpatched kernel #299736

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

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[alyssais]

This has broken rust-out-of-tree-module for kernels with Rust support, which you can reproduce by attempting to evaluate nixosTests.kernel-rust. Would you mind having a look?

error:
       … while evaluating the attribute 'drvPath'
         at /home/qyliss/src/nixpkgs/lib/customisation.nix:365:7:
          364|     in commonAttrs // {
          365|       drvPath = assert condition; drv.drvPath;
             |       ^
          366|       outPath = assert condition; drv.outPath;

       … while calling the 'derivationStrict' builtin
         at <nix/derivation-internal.nix>:9:12:
            8|
            9|   strict = derivationStrict drvAttrs;
             |            ^
           10|

       … while evaluating the option `nodes.machine.system.systemBuilderCommands':

       … while evaluating definitions from `/home/qyliss/src/nixpkgs/nixos/modules/system/boot/kernel.nix':

       (stack trace truncated; use '--show-trace' to show the full, detailed trace)

       error: Package ‘rust-out-of-tree-module’ in /home/qyliss/src/nixpkgs/pkgs/os-specific/linux/rust-out-of-tree-module/default.nix:21 is marked as broken, refusing to evaluate.

       a) To temporarily allow broken packages, you can use an environment variable
          for a single invocation of the nix tools.

            $ export NIXPKGS_ALLOW_BROKEN=1

          Note: When using `nix shell`, `nix build`, `nix develop`, etc with a flake,
                then pass `--impure` in order to allow use of environment variables.

       b) For `nixos-rebuild` you can set
         { nixpkgs.config.allowBroken = true; }
       in configuration.nix to override this.

       c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
         { allowBroken = true; }
       to ~/.config/nixpkgs/config.nix.

[roberth]

@alyssais Sorry about that, my mistake. This fixes the eval: #308763