Show test failures as GH Actions annotations

[ximon18]

E.g.

See also:

• https://github.community/t5/GitHub-Actions/What-are-annotations/td-p/30770
• https://github.community/t5/GitHub-Actions/Best-practices-when-creating-annotations-from-an-action/td-p/30977
• https://github.com/pytorch/add-annotations-github-action
• https://github.com/ember-template-lint/ember-template-lint/pull/966

It's unclear to me at this point what the current status of support for GH Annotations is from within GH Actions workflows or how to use them.