feat: remove useless vanilla test (opensearch-project#975)

* feat: skip flaky test

Signed-off-by: SuZhou-Joe <suzhou@amazon.com>

* feat: remove useless test case

Signed-off-by: SuZhou-Joe <suzhou@amazon.com>

* feat: remove useless reference

Signed-off-by: SuZhou-Joe <suzhou@amazon.com>

---------

Signed-off-by: SuZhou-Joe <suzhou@amazon.com>

Author: SuZhou-Joe

.github/workflows/cypress-workflow-vanilla-snapshot-based.yml

@@ -76,7 +76,7 @@ To run tests against a local cluster
 without security:
 
 ```
-$ yarn cypress:run-without-security --spec "cypress/integration/core-opensearch-dashboards/vanilla-opensearch-dashboards/*.js"
+$ yarn cypress:run-without-security --spec "cypress/integration/core-opensearch-dashboards/opensearch-dashboards/*.js"
 ```
 
 with security: