update for bundler 4, :mingw, :x64_mingw, :mswin have been removed

Author: thermistor

Gemfile

@@ -21,7 +21,7 @@ group :jekyll_plugins do
   gem 'jekyll-sitemap'
 end
 
-platforms :mingw, :x64_mingw, :mswin, :jruby do
+platforms :windows, :jruby do
   gem 'tzinfo', '>= 1', '< 3'
   gem 'tzinfo-data'
 end