merge-queue is marking builds as FAILURE when it successfully lands P…

…R after retry

https://bugs.webkit.org/show_bug.cgi?id=234644

Reviewed by Jonathan Bedard.

Set overall build status as SUCCESS (green) if the commit was successful.

* Tools/CISupport/ews-build/steps.py:
(SetBuildSummary.start):

Canonical link: https://commits.webkit.org/266880@main

Tools/CISupport/ews-build/steps.py

@@ -5121,6 +5121,8 @@ def start(self):
         previous_build_summary = self.getProperty('build_summary', '')
         if RunWebKitTestsInStressMode.FAILURE_MSG_IN_STRESS_MODE in previous_build_summary:
             self.build.results = FAILURE
+        elif 'Committed ' in previous_build_summary and '@' in previous_build_summary:
+            self.build.results = SUCCESS
         self.build.buildFinished([build_summary], self.build.results)
         return defer.succeed(None)