nixos/ksm: Enhancements and new ksmtuned package.

[kmcopper]

Motivation for this change

#73095 partially gave me the idea to work on this patch set to help unload udev-settle. I worked some additional enhancements to the ksm configuration while I was at it.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

There aren't really any of these for ksm but I would appreciate anybodies input on this

[kmcopper]

Oops, looks like my maintainer attribute is tied up in #53032 and that's why the check fails here vs when I tested it.

[kmcopper]

@GrahamcOfBorg eval
@GrahamcOfBorg build ksmtuned

[stale]

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