Exclude browser stability tests for exports from that specific browser …

…#31898 (username update) (#31941)

tools/ci/tc/decision.py

@@ -105,9 +105,9 @@ def filter_jobs(jobs, event):
 
     # Exclude browser stability tests for exports from that specific browser.
     try:
-        if event["sender"]["login"] == "chromium-wpt-export-bot":
+        if event["pull_request"]["user"]["login"] == "chromium-wpt-export-bot":
             jobs.discard("wpt-chrome-dev-stability")
-        if event["sender"]["login"] == "moz-wptsync-bot":
+        if event["pull_request"]["user"]["login"] == "moz-wptsync-bot":
             jobs.discard("wpt-firefox-nightly-stability")
     except KeyError:
         # Just continue if the username cannot be pulled from the event.