SEC-10095 test(cypress): demote unstable tests (#36099)

* test(cypress): demote unstable tests

* follow fixes

* fix merging playwright reports

e2e-tests/cypress/tests/integration/channels/system_console/site_configuration/announcement_banner_spec.js

@@ -7,7 +7,6 @@
 // - Use element ID when selecting an element. Create one if none.
 // ***************************************************************
 
-// Stage: @prod
 // Group: @channels @enterprise @system_console @announcement_banner
 
 import {hexToRgbArray, rgbArrayToString} from '../../../../utils';

e2e-tests/cypress/tests/integration/channels/system_console/site_configuration/customization_spec.js

@@ -7,7 +7,6 @@
 // - Use element ID when selecting an element. Create one if none.
 // ***************************************************************
 
-// Stage: @prod
 // Group: @channels @system_console
 
 import * as TIMEOUTS from '../../../../fixtures/timeouts';

e2e-tests/cypress/tests/integration/channels/system_console/user_management_spec.js

@@ -7,7 +7,6 @@
 // - Use element ID when selecting an element. Create one if none.
 // ***************************************************************
 
-// Stage: @prod
 // Group: @channels @system_console
 
 import {