Remove Gemfile.lock for Ruby head

Author: andyw8

.github/workflows/ci.yml

@@ -28,8 +28,8 @@ jobs:
       - uses: actions/checkout@v3
 
       - name: Remove Gemfile.lock
-        if: matrix.os == 'windows-latest' && matrix.ruby == '3.1'
-        run: rm Gemfile.lock
+        if: (matrix.ruby == 'head' ) || (matrix.os == 'windows-latest' && matrix.ruby == '3.1')
+        run: "rm ${{ matrix.gemfile }}.lock"
 
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1