Gem::Installer#generate_bin_script

# File tmp/rubies/ruby-3.0.5/lib/rubygems/installer.rb, line 533
def generate_bin_script(filename, bindir)
  bin_script_path = File.join bindir, formatted_program_filename(filename)

  require 'fileutils'
  FileUtils.rm_f bin_script_path # prior install may have been --no-wrappers

  File.open bin_script_path, 'wb', 0755 do |file|
    file.print app_script_text(filename)
    file.chmod(options[:prog_mode] || 0755)
  end

  verbose bin_script_path

  generate_windows_script filename, bindir
end