chore: update release workflow to trigger on pull requests and conditionally push Docker images

Author: sirily11

.github/workflows/release.yaml

@@ -1,6 +1,9 @@
 name: Release
 
 on:
+  pull_request:
+    branches:
+      - main
   release:
     types:
       - created
@@ -52,7 +55,7 @@ jobs:
         with:
           context: .
           platforms: linux/amd64
-          push: true
+          push: ${{ github.event_name == 'release' }}
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           build-args: |
@@ -66,6 +69,7 @@ jobs:
     name: Deploy to Kubernetes
     needs: docker-release
     runs-on: ubuntu-latest
+    if: github.event_name == 'release'
     permissions:
       contents: read
     steps: