Accommodate for yet another change on GitHub's backend

As of very recent, the webhooks triggered by completed Check Runs no
longer report the `gitforwindowshelper[bot]` as the sender, if that bot
completed the Check Run, but `ghost`.

That is incorrect, of course, but there is nothing we can do about it
except what we always do when GitHub changes the way their platform
behaves: We adapt.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

GitForWindowsHelper/cascading-runs.js

@@ -115,7 +115,8 @@ const cascadingRuns = async (context, req) => {
     const checkRunRepo = req.body.repository.name
     const checkRun = req.body.check_run
     const name = checkRun.name
-    const sender = req.body.sender.login
+    const sender = req.body.sender.login === 'ghost' && checkRun?.app?.slug === 'gitforwindowshelper'
+        ? 'gitforwindowshelper[bot]' : req.body.sender.login
 
     if (action === 'completed') {
         if (name === 'tag-git') {