elixir: Add runnable tasks (#12526)

Release Notes:

- Added runnable tasks to Elixir tests (modules, `describe` and `test`
blocks)


https://github.com/zed-industries/zed/assets/7737375/06f1b4cb-0364-4c30-982d-6dda3193b5d2
a6e0c8aca1João Otávio Biondo committed on 5/31/2024, 6:49:34 PM· committed by GitHubparentd12b8c3
2 files changedLine totals unavailable