Chore: remove scenario wrapping in cypress tests (#74674)

* remove scenario wrapping in cypress tests

* remove more hardcoded logins

* don't forget the various suite!

* make sure we log in for every test

* fix afterAll revert

* stability

e2e/dashboards-suite/new-datasource-variable.spec.ts

@@ -4,8 +4,11 @@ const PAGE_UNDER_TEST = 'kVi2Gex7z/test-variable-output';
 const DASHBOARD_NAME = 'Test variable output';
 
 describe('Variables - Datasource', () => {
+  beforeEach(() => {
+    e2e.flows.login(e2e.env('USERNAME'), e2e.env('PASSWORD'));
+  });
+
   it('can add a new datasource variable', () => {
-    e2e.flows.login('admin', 'admin');
     e2e.flows.openDashboard({ uid: `${PAGE_UNDER_TEST}?orgId=1&editview=templating` });
     cy.contains(DASHBOARD_NAME).should('be.visible');