Show bug blocking migration due to dependent test failures

[Andreas Hasenack]

The way the update-excuse tag works now, if I'm not mistaken, is that it is expected on the uploaded package, but doesn't track bugs in the packages that had their tests run as a dependency.

For example, the ruby2.5 upload triggered a bunch of ruby-* dep8 runs, one of which (ruby-ferret) failed. I added the update-excuse tag to the ruby-ferret bug about the test failure (#1843804), but that doesn't show up in the ruby2.5 excuses entry. I then added a ruby2.5 task to #1843804, and then the excuses page is showing the bug.

The ruby-ferret failure is also preventing glibc2.30 from migrating, but the glibc2.30 task is set to invalid (because it's not a gibc bug) and the excuses page is ignoring not-open bugs.

What I'm asking for, is that the summary of the excuses page for each package displays the bugs with the update-excuse tag for not only the uploaded package (the package that triggered all the test runs), but also for any packages that are below it.