linuxManualConfig: add pahole to moduleBuildDependencies

[alyssais]

Description of changes

This seems to be needed for out-of-tree module builds since #221707. We do not yet understand why, but this will unblock the channels while we figure it out.

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• 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/)
• 23.05 Release Notes (or backporting 22.11 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.

[alyssais]

@ofborg build linuxPackages.zfs

[alyssais]

@ofborg build linuxPackages.zfs

[alyssais]

Before #221707, out of tree module builds had lines like this:

Skipping BTF generation for /build/source/kernel/linux/ena/ena.ko due to unavailability of vmlinux

And then, after #221707, those lines went away, and they started failing due to not having pahole.

So what happened here is that we had a bug, which was that vmlinux was not available where out-of-tree module builds expected it to be, and when I moved vmlinux so it was in the right place for the GDB scripts, I fixed that bug by accident. That introduced a new bug, which was that out-of-tree modules would try to generate BTF, but fail due to not having pahole. When I added pahole in this PR, that fixed that bug too. So I think everything is good now.

[Ma27]

Just want to state that I'm very grateful for your work on this!