Previous setups will already contain folders created as root. Making a different user the default
will break these setups. So just make it opt-in instead.
This removes the need for all the ruby-lsp setup stuff.
ruby-lsp will try to install the debug gem which contains native code, add that to the gemfile so it doesn't cause trouble.
I'm probably going to remove the rubocop/test compose services at some point. With devcontainers you are just able to run the commands directly.