Fix E2E test reporting message for webhook (#29304)

* Fix testcases failing  Webpack compilation
* Fix E2E test report message for webhook
* Demote more unstable tests
* Fix playwright reporting message, better test demotion

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Co-authored-by: Mattermost Build <build@mattermost.com>

e2e-tests/cypress/tests/integration/channels/collapsed_reply_threads/channel_notifications_spec.ts

@@ -7,7 +7,6 @@
 // - Use element ID when selecting an element. Create one if none.
 // ***************************************************************
 
-// Stage: @prod
 // Group: @channels @collapsed_reply_threads
 
 import {Team} from '@mattermost/types/teams';