Bump docker/build-push-action from 5 to 6 (#59)

Author: sjoerdsimons

.github/workflows/ci.yml

@@ -98,7 +98,7 @@ jobs:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         if: github.event_name != 'pull_request'
         with:
           context: .