ci: notification from Dashboard

Created by: cathales

Context

Pull requests targeting branch cva6/dev trigger jobs on an external infrastructure. However, results are not easily accessible from the GitHub PR.

PR description

To make it easier for PR authors and reviewers to access the results of these jobs, the external infrastructure will send a comment in the PR with a link to the job results when they are available. It is done in a two-step process:

GitHub side

So that the comment is created by a bot and not a specific individual, the comment should be created by a workflow. This new workflow is triggered only manually, and takes two parameters: the PR number and the exit status of the job, to write a comment accordingly.

GitLab side

We use GitHub API to trigger the workflow when the job ends.