Don't run unit tests within the System Tests GitHub Actions stage

Author: rosswilson

railties/lib/rails/generators/rails/app/templates/github/ci.yml.tt

@@ -215,7 +215,7 @@ jobs:
           <%- end -%>
           # RAILS_MASTER_KEY: ${{ secrets.RAILS_MASTER_KEY }}
           # REDIS_URL: redis://localhost:6379/0
-        run: bin/rails db:test:prepare test test:system
+        run: bin/rails db:test:prepare test:system
 
       - name: Keep screenshots from failed system tests
         uses: actions/upload-artifact@v4