Fix bundler warning

This config is only ran in CI so I didn't see it when
I introduced it,.

Warning message:
```
Run bundle config --without benchmark
[DEPRECATED] Using the `config` command without a subcommand [list, get, set, unset] is deprecated and will be removed in the future. Use `bundle config set --without benchmark` instead.
```

Author: stefannibrasil

.github/workflows/ruby.yml

@@ -55,7 +55,7 @@ jobs:
 
     - name: Install dependencies
       run: |
-        bundle config --without benchmark
+        bundle config set --without benchmark
         bundle install
 
     - name: Run tests