The following warning appeared when starting devcontainer.
```
WARN[0000] /home/***/ghq/github.com/rails/rails/.devcontainer/compose.yaml: `version` is obsolete
WARN[0000] /tmp/devcontainercli-***/docker-compose/docker-compose.devcontainer.build-1720224621191.yml: `version` is obsolete
```
In fact, the top-level version element will be obsolete in the compose specification.
https://github.com/compose-spec/compose-spec/blob/master/spec.md#version-top-level-element-obsolete
And stop exposing the capybara server port to all interfaces.
We were using this just to make sure the selenium container can access
the capybara server but it can with the default bridge network.