add nvm versin

Jenkinsfile

         }
         stage('install dependencies') {
             steps {
-                sh 'npm install'
+                nvm( version : '12.22.9' ){
+                    sh 'npm install'
+                }
             }
         }
         stage('build') {
             steps {
-                sh 'npm run build'
+                nvm( version : '12.22.9' ){
+                    sh 'npm run build'
+                }
             }
         }
     }