enhance: send email to qa when nightly ci failure

Signed-off-by: Yellow Shine <[email protected]>

ci/jenkins/Nightly2.groovy

@@ -1,4 +1,4 @@
-@Library('jenkins-shared-library@v0.53.0') _
+@Library('jenkins-shared-library@v0.56.0') _
 
 def pod = libraryResource 'io/milvus/pod/tekton-4am.yaml'
 
@@ -134,5 +134,14 @@ pipeline {
                 }
             }
         }
+        post {
+            unsuccessful {
+                container('jnlp') {
+                    script {
+                        sendEmail.toQA()
+                    }
+                }
+            }
+        }
     }
 }