chore(ci): do not run all-green job on pushes on main (#13302)

## Checklist
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[release branch maintenance
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Author: cbeauchesne

.github/workflows/all-green.yml

@@ -1,9 +1,6 @@
 name: All Green
 on:
   pull_request:
-  push:
-    branches:
-      - main
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}