Fix Ruby warnings

```console
$ bundle exec rake
~/.local/share/mise/installs/ruby/3.4.3/lib/ruby/gems/3.4.0/gems/serverkit-1.0.0/lib/serverkit/resources/base.rb:93: warning: method redefined; discarding old id
~/.local/share/mise/installs/ruby/3.4.3/lib/ruby/gems/3.4.0/gems/serverkit-1.0.0/lib/serverkit/resources/base.rb:26: warning: previous definition of id was here
```