Fix build on PR

Author: tomquist

.github/workflows/build-image.yml

@@ -71,7 +71,23 @@ jobs:
           registry: ${{ inputs.registry }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Build
+        if: github.event_name == 'pull_request'
+        id: build
+        uses: docker/build-push-action@v5
+        with:
+          context: ${{ inputs.context }}
+          platforms: ${{ inputs.platform }}
+          file: ${{ inputs.dockerfile }}
+          labels: ${{ steps.meta.outputs.labels }}
+          outputs: type=docker,name=${{ env.REGISTRY }}/${{ steps.lower-repo.outputs.IMAGE_NAME }}
+          build-args: |
+            ${{ inputs.build-args }}
+            BASE=${{ inputs.base }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
       - name: Build and push by digest
+        if: github.event_name != 'pull_request'
         id: build
         uses: docker/build-push-action@v5
         with:
@@ -87,6 +103,7 @@ jobs:
           cache-from: type=gha
           cache-to: type=gha,mode=max
       - name: Export digest
+        if: github.event_name != 'pull_request'
         run: |
           mkdir -p /tmp/digests
           digest="${{ steps.build.outputs.digest }}"
@@ -97,6 +114,7 @@ jobs:
           SAFE_PLATFORM=$(echo "${{ inputs.platform }}" | sed 's|/|-|g')
           echo "name=$SAFE_PLATFORM" >> $GITHUB_OUTPUT
       - name: Upload digest
+        if: github.event_name != 'pull_request'
         uses: actions/upload-artifact@v4
         with:
           name: ${{ inputs.digest-prefix }}${{ steps.platform.outputs.name }}