feat: activate Cardano node version '9.1.0' in e2e test in CI

Author: jpraynaud

.github/workflows/ci.yml

@@ -289,7 +289,7 @@ jobs:
       matrix:
         mode: ["std"]
         era: ${{ fromJSON(needs.build-ubuntu-X64.outputs.eras) }}
-        cardano_node_version: ["8.9.4", "8.12.2", "9.0.0", "8.12.0-pre"]
+        cardano_node_version: ["8.9.4", "8.12.2", "9.0.0", "9.1.0"]
         hard_fork_latest_era_at_epoch: [0]
         run_id: ["#1"]
         extra_args: [""]