[skip e2e] Add comment to scale test stage (#14946)

Signed-off-by: ThreadDao <yufen.zong@zilliz.com>

build/ci/jenkins/Scale.groovy

@@ -51,6 +51,7 @@ pipeline {
                 container('milvus-test') {
                     dir ('tests/python_client/scale') {
                         script {
+                            // pytest run scale case in parallel
                             sh 'pytest . -n 5 -v -s'
                         }
                     }