Bump zombienet version `v1.3.115` (#6065)

Includes:
- Fixes for `ci`
- Support to pass a json as arg for `js-script`

Co-authored-by: Bastian Köcher <git@kchr.de>

.gitlab/pipeline/zombienet.yml

 .zombienet-refs:
   extends: .build-refs
   variables:
-    ZOMBIENET_IMAGE: "docker.io/paritytech/zombienet:v1.3.114"
+    ZOMBIENET_IMAGE: "docker.io/paritytech/zombienet:v1.3.115"
     PUSHGATEWAY_URL: "http://zombienet-prometheus-pushgateway.managed-monitoring:9091/metrics/job/zombie-metrics"
     DEBUG: "zombie,zombie::network-node,zombie::kube::client::logs"
     ZOMBIE_PROVIDER: "k8s"