Change the trigger for the Istio CNI github action

Trigger the test on every PR which changes istio-cni code only.

Signed-off-by: Tzvetomir Stoyanov (VMware) <[email protected]>

.github/workflows/kserve_kind_cni_test.yaml

@@ -2,9 +2,7 @@ name: Build & Apply KServe manifests in KinD, using istio CNI
 on:
   pull_request:
     paths:
-      - contrib/kserve/**
-      - common/knative/**
-  workflow_dispatch:
+      - common/istio-cni-1-17/**
 
 jobs:
   build: