Add ubuntu builds to gitlab CI
https://gitlab.haskell.org/maerwald/haskell-language-server/-/pipelines/56839
Still issues with the tar job
https://gitlab.haskell.org/maerwald/haskell-language-server/-/pipelines/56845
https://gitlab.haskell.org/maerwald/haskell-language-server/-/pipelines/57272
I've fixed the build, along with a fix for #3162: https://gitlab.haskell.org/haskell/haskell-language-server/-/pipelines/57254
gitlab pipeline succeeded: https://gitlab.haskell.org/maerwald/haskell-language-server/-/pipelines/57533
This is for the old gitlab CI