Install Bundler forcely on Windows

Author: aycabta

.github/workflows/windows.yml

@@ -15,7 +15,7 @@ jobs:
       with:
         ruby-version: ${{ matrix.ruby }}
     - name: Set up Bundler
-      run: gem install bundler --no-document
+      run: gem install bundler --no-document --force
     - name: Install dependencies
       run: bundle install
     - name: Run test