zsh: killed git on Mac
Assuming you used the brew reinstall git command instead of brew install git, and assuming you still have Command Line Tools installed, then I would first install gettext and pcre2 as git needs them.
So, first do...
brew reinstall gettext

...followed by:
brew reinstall pcre2

and then by...
brew reinstall git

If that doesn't work you could try all the commands again but with install instead of reinstall.
And if that doesn't work, what's the result of brew config?