Fix RubyInline problem by using Gemfile

.github/workflows/main.yml

@@ -23,17 +23,6 @@ jobs:
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true
-    - name: Fix RubyInline
-      if: matrix.os == 'windows-latest'
-      shell: cmd
-      run: |
-        start /b /wait ruby -e "exit(Gem::Version.new('${{ matrix.ruby }}') >= Gem::Version.new('3.1') ? 0 : 1)"
-        if %errorlevel% == 0 (
-          gem install specific_install hoe minitest
-          gem specific_install https://github.com/rdp/specific_install.git # to use -i 
-          gem specific_install -i vendor/bundle https://github.com/fenrir-naru/rubyinline.git fix_windoze
-        )
-        cd >nul
     - name: Run the default task
       run: bundle exec rake
 #      env:

Gemfile

@@ -4,3 +4,9 @@ source "https://rubygems.org"
 
 # Specify your gem's dependencies in gps_pvt.gemspec
 gemspec
+
+if /mingw/ =~ RUBY_PLATFORM then
+  gem "RubyInline",
+      :git => 'https://github.com/fenrir-naru/rubyinline.git',
+      :branch => 'fix_windoze'
+end