Remove ill-working CI hack

.github/workflows/ci.yml

@@ -3,12 +3,6 @@ name: CI
 on:
   push:
   pull_request:
-    branches:
-      # Branches from forks have the form 'user:branch-name' so we only run
-      # this job on pull_request events for branches that look like fork
-      # branches. Without this we would end up running this job twice for non
-      # forked PRs, once for the push and then once for opening the PR.
-      - "**:**"
   schedule:
     - cron: "0 3 * * 1" # Every monday at 3 AM