chore(deps): update gcr.io/cloud-devrel-public-resources/storage-testbench docker tag to v0.56.0

Author: renovate-bot

.github/workflows/conformance-tests-storage-emulator.yaml

@@ -16,7 +16,7 @@ jobs:
 
     services:
       emulator:
-        image: gcr.io/cloud-devrel-public-resources/storage-testbench:v0.55.0
+        image: gcr.io/cloud-devrel-public-resources/storage-testbench:v0.56.0
         ports:
           - 9000:9000