github: simplify building only on push events

Signed-off-by: Simon Deziel <[email protected]>

.github/workflows/builds.yml

@@ -1,6 +1,5 @@
 name: Builds
 on:
-  pull_request:
   push:
     branches:
       - 5.21-candidate
@@ -16,7 +15,7 @@ jobs:
   snap:
     name: Trigger snap build
     runs-on: ubuntu-24.04
-    if: ${{ github.repository == 'canonical/lxd-pkg-snap' && github.event_name == 'push' && github.actor != 'dependabot[bot]' }}
+    if: ${{ github.repository == 'canonical/lxd-pkg-snap' && github.actor != 'dependabot[bot]' }}
     steps:
       - name: Checkout code
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # v4.2.2