[6.x] skip flaky discover test (#13114)

[stacey-gammon]

Caused last 4 builds to fail on master.

Will attempt to bring back in
#13034

backports #13114

[stacey-gammon]

Failed on:

01:07:04.282      └-> Warns when case is different
01:07:04.282        └-> "before each" hook: global before each
01:07:04.288          │ debg  Kibana uiSettings are in elasticsearch and the server is reporting a green status
01:07:04.288        │ debg  Clicking edit
01:07:04.290        │ debg  in findTestSubject: [data-test-subj~="dashboardEditMode"]
01:07:04.404        │ debg  in findTestSubject: [data-test-subj~="dashboardSaveMenuItem"]
01:07:04.521        │ debg  in findTestSubject: [data-test-subj~="globalLoadingIndicator"]
01:07:06.595        │ debg  entering new title
01:07:06.914        │ debg  clicking final Save button for named dashboard
01:07:06.915        │ debg  in findTestSubject: [data-test-subj~="confirmSaveDashboardButton"]
01:07:07.025        │ debg  in findTestSubject: [data-test-subj~="confirmModalCancelButton"]
01:07:09.105        │ debg  Taking screenshot "/var/lib/jenkins/workspace/elastic+kibana+pull-request+multijob-selenium/test/functional/screenshots/failure/dashboard app dashboard save Warns when case is different.png"
01:07:09.230      └- ✖ fail: "dashboard app dashboard save Warns when case is different"
01:07:09.230      │        Error: expected false to equal true

We may have another flaky dashboard test in our midst...

jenkins, test this