[mix][library][test] refactor mix_test to use mix_library compilation artifacts and use a mix_env environment for library compilation#2

arikaro-disc wants to merge 2 commits intomaindiscord/rules_elixir:mainfrom

akaro/mix-library-test-artifactsdiscord/rules_elixir:akaro/mix-library-test-artifactsCopy head branch name to clipboard