Daily E2E test fixes (#29580)

* [skip ci] Stabilize testcases, clean reporting for nighly unstables

* [skip ci] Better output naming

* [skip ci] Fix testcase failure fatal condition

* [skip ci] Make linter happy

* [skip ci] Revert global beforeEach change

* [skip ci] Fix workflow file, skip unstable tests

* [skip ci] Fix testcase_failure_fatal templating

e2e-tests/cypress/tests/integration/channels/mark_as_unread/leave_channel_unread_spec.js

@@ -24,6 +24,7 @@ describe('Leaving channel', () => {
     let post1;
 
     beforeEach(() => {
+        cy.visit('/');
         cy.apiAdminLogin();
         cy.apiInitSetup().then(({team, channel, user}) => {
             testUser = user;