Gem::Commands::EnvironmentCommand#git_path

# File tmp/rubies/ruby-3.0.5/lib/rubygems/commands/environment_command.rb, line 163
def git_path
  exts = ENV["PATHEXT"] ? ENV["PATHEXT"].split(";") : [""]
  ENV["PATH"].split(File::PATH_SEPARATOR).each do |path|
    exts.each do |ext|
      exe = File.join(path, "git#{ext}")
      return exe if File.executable?(exe) && !File.directory?(exe)
    end
  end

  return nil
end