build: temporarily disable metacov, it's flaky now with sysmon support

Author: nedbat

.github/workflows/coverage.yml

@@ -8,7 +8,9 @@ on:
   # on pull requests yet.
   push:
     branches:
-      - master
+      # sys.monitoring somehow broke metacoverage, so turn it off while we fix
+      # it and get a sys.monitoring out the door.
+      #- master
       - "**/*metacov*"
   workflow_dispatch: