Fix Jenkins agent label: use 'agent any' instead of 'label any'

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Entire-Checkpoint: 1502e571778c

Jenkinsfile

@@ -19,7 +19,7 @@ pipeline {
 
   stages {
     stage('Docker Image') {
-      agent { label 'any' }
+      agent any
       steps {
         script {
           echo "Checking if Docker image exists locally..."