Publish builds should point to nuget.org not CI feed

Author: kzu

.github/workflows/publish.yml

@@ -15,7 +15,7 @@ env:
   VersionLabel: ${{ github.ref }}
   GH_TOKEN: ${{ secrets.GH_TOKEN }}
   MSBUILDTERMINALLOGGER: auto
-  SLEET_FEED_URL: ${{ vars.SLEET_FEED_URL }}
+  SLEET_FEED_URL: https://api.nuget.org/v3/index.json
 
 jobs:
   publish: