#5883 showed that failures on CI were going unnoticed (see #5954, #5953).
To prevent having to check CI history manually, @apoelstra proposed setting up a flow that creates issues automatically.

I set this up and tested it in a test-repo, for two dummy Kani CI and Fuzz workflows.

Current scope:

1. The Kani CI and Fuzz workflows are tracked
2. On workflow failure, an issue is created
3. During a given failure streak, the same issue is re-used and updated
4. On the next successful run, a success comment is added to the issue and the issue is closed

Example issues can be reviewed here and here.