ci release: remove redundant step

Author: kou

.github/workflows/release.yml

@@ -53,9 +53,6 @@ jobs:
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ruby
-      - name: Build gems
-        run: |
-          rake build
       - uses: rubygems/configure-rubygems-credentials@v1.0.0
       - name: Push gems
         run: |