Update k8s version logic (#8379)

Author: vepatel

.github/workflows/update-kubernetes-version.yml

@@ -5,7 +5,7 @@ on:
       - main
       - release-*
     paths:
-      - tests/Dockerfile
+      - tests/Makefile
 
 concurrency:
   group: ${{ github.ref_name }}-k8s-version
@@ -23,7 +23,7 @@ jobs:
       - name: Get current k8s version from Kind image
         id: k8s-version
         run: |
-          v=$(grep kindest tests/Dockerfile | cut -d ':' -f 2 | cut -d '@' -f 1)
+          v=$(grep "^K8S_CLUSTER_VERSION" tests/Makefile | awk '{ print $3 }')
           echo "version=${v}" >> $GITHUB_OUTPUT
           cat $GITHUB_OUTPUT