Run pull request validation once through native CI

.gitea/workflows/build-and-push.yml

@@ -4,14 +4,16 @@ on:
   push:
     branches:
     - master
-      - main
     tags:
     - v*
-  workflow_dispatch:
+  workflow_dispatch: null
+  pull_request:
+    branches:
+    - master
 
 jobs:
   build-and-push:
-    runs-on: ubuntu-latest
+    runs-on: butler-ci
     env:
       REGISTRY: gitea.wayfinderak.com
       IMAGE_NAME: gitea.wayfinderak.com/wayfinderak/geeksbot
@@ -77,7 +79,7 @@ jobs:
         run: go test ./...
 
       - name: Log in to Gitea Container Registry
-        if: ${{ steps.delivery.outputs.run == 'true' }}
+        if: ${{ (steps.delivery.outputs.run == 'true') && github.event_name != 'pull_request' }}
         shell: bash
         run: |
           set -euo pipefail
@@ -139,7 +141,7 @@ jobs:
           docker build "${build_args[@]}" .
 
       - name: Push image
-        if: ${{ steps.delivery.outputs.run == 'true' }}
+        if: ${{ (steps.delivery.outputs.run == 'true') && github.event_name != 'pull_request' }}
         shell: bash
         run: |
           set -euo pipefail