Update update_homebrew.yml

.github/workflows/update_homebrew.yml

@@ -14,6 +14,20 @@ jobs:
   homebrew-publish:
     runs-on: ubuntu-latest
     steps:
+    - name: Set up Homebrew
+      id: set-up-homebrew
+      uses: Homebrew/actions/setup-homebrew@master
+    - name: Cache Homebrew Bundler RubyGems
+      id: cache
+      uses: actions/cache@v1
+      with:
+        path: ${{ steps.set-up-homebrew.outputs.gems-path }}
+        key: ${{ runner.os }}-rubygems-${{ steps.set-up-homebrew.outputs.gems-hash }}
+        restore-keys: ${{ runner.os }}-rubygems-
+
+    - name: Install Homebrew Bundler RubyGems
+      if: steps.cache.outputs.cache-hit != 'true'
+      run: brew install-bundler-gems
     - name: Bump formulae
       uses: Homebrew/actions/bump-formulae@master
       with: