[ci] Don't run on push (#1882) (#2394)

We already have the merge queue; running on push is redundant.

gherrit-pr-id: I48ecff7f2ed189bf87ba0dcb451345c0d0278b83

Author: joshlf

.github/workflows/ci.yml

@@ -10,10 +10,6 @@ name: Build & Tests
 
 on:
   pull_request:
-  push:
-    branches:
-      - main
-      - v0.8.x
   merge_group:
 
 permissions: read-all