chore: fix build for latest ruby version

Gemfile

@@ -1,21 +1,6 @@
 source "https://rubygems.org"
-# Hello! This is where you manage which Jekyll version is used to run.
-# When you want to use a different version, change it below, save the
-# file and run `bundle install`. Run Jekyll with `bundle exec`, like so:
-#
-#     bundle exec jekyll serve
-#
-# This will help ensure the proper Jekyll version is running.
-# Happy Jekylling!
-#gem "jekyll", "~> 4.1.0"
-# This is the default theme for new Jekyll sites. You may change this to anything you like.
-gem "minima", "~> 2.5"
-# If you want to use GitHub Pages, remove the "gem "jekyll"" above and
-# uncomment the line below. To upgrade, run `bundle update github-pages`.
-gem "github-pages"
-# If you have any plugins, put them here!
+
 group :jekyll_plugins do
-  # gem "jekyll-feed", "~> 0.12"
   gem 'jekyll-admin'
   gem 'jekyll-scholar'
   gem 'jekyll-spaceship'
@@ -33,3 +18,7 @@ end
 # Performance-booster for watching directories on Windows
 gem "wdm", "~> 0.1.1", :platforms => [:mingw, :x64_mingw, :mswin]
 
+
+gem "webrick", "~> 1.8"
+
+gem "jekyll-github-metadata", "~> 2.16"