Move webrick to development as it's used in tests

Author: kateinoigakukun

Gemfile

@@ -8,11 +8,11 @@ group :development do
   gem "rake"
   gem "rake-compiler"
   gem "rb_sys", "0.9.97"
+  # Use the latest version of webrick for URI change in Ruby 3.4
+  gem "webrick", "~> 1.8.2"
 end
 
 group :check do
-  # Use the latest version of webrick for URI change in Ruby 3.4
-  gem "webrick", "~> 1.8.2"
   gem "syntax_tree", "~> 3.5"
   gem "steep", "~> 1.9"
 end