Update docker/build-push-action digest to a8d3541

Author: renovate[bot]

.github/workflows/ci.yaml

@@ -101,7 +101,7 @@ jobs:
       - name: Build Docker image
         id: push
         timeout-minutes: 25
-        uses: docker/build-push-action@090ca155fc9b214cbcac536c450455a0e96f52c6
+        uses: docker/build-push-action@a8d35412fb758de9162fd63e3fa3f0942bdedb4d
         with:
           context: .
           load: false