feat(tvix/cli): add benchmark for bf286a54bc r/7171

cl/7558 used this expression as a benchmark to justify the introduction
of LightSpan::Delayed:

  builtins.length (builtins.attrNames (import ${pkgs.path} {}))

Let's add it as a benchmark case so it can be referenced easily.

Benchmark: {"nixpkgs-attrnames":{"kbytes":"233824","system":"0.32","user":"2.02"}}
Change-Id: Idb6c69ddd284605dd3b5fd9ac5c79a69b9a470b7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10253
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions