Zsh benchmark is meaningless

[z0rc]

Describe the bug Timing zsh -lic "exit" (as in https://github.com/yutkat/dotfiles/blob/main/.github/scripts/benchmark.sh#L5) is not a benchmark, as its results are not what you expect. For details why it is so, read https://github.com/romkatv/zsh-bench#how-not-to-benchmark

Additional context dotfiles.github.io says about this repo as "Using CI to test and measure startup speed.", but this statement isn't true.

[yutkat]

Thanks for the info, I knew I could measure correctly if I used zsh-bench. I'll try switching next time.

[yutkat]

Fixed https://github.com/yutkat/dotfiles/pull/3540/files