TT#108003 run coverity test on a schedule

Change-Id: I1fdd0178ff2f5885718427eb7a974b40220bce9d

.github/workflows/coverity.yml

@@ -4,6 +4,8 @@ on:
   push:
     branches:
       - coverity_scan
+  schedule:
+    - cron: '13 4 */2 * *'
 
   workflow_dispatch: