added chanes to jenkins file

jenkinsfile

@@ -0,0 +1,25 @@
+pipeline {
+    agent{ label 'MAVEN' | 'JDK_17' }
+    options { timeout(time: 30, unit: 'MINUTES') }
+    triggers{
+        pollSCM ( * * * * * )
+    }
+    environment
+    {
+        mypassword = helloadmin
+    }
+    stages{
+        stage('git'){
+            steps {
+                git url: 'https://github.com/srikanthkuna1618/spring-petclinic-march.git', 
+                branch: 'dev' 
+            }
+        }
+        stage('build') {
+            steps {
+                sh 'mvn  clean package'
+            }
+        }
+
+    }
+}