test: remove useless navigation to /login while logging in via command

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/1795>

front/cypress/support/commands.ts

@@ -1,13 +1,8 @@
-// Currently we cannot login purely programmatically, so we need to use the
-// graphical login until the vue3 branch is merged
 Cypress.Commands.add('login', () => {
   cy.fixture('testuser.json').then(({ username, password }) => {
     // We need to request a page that sets the csrf cookie
     cy.request('/api/v1/instance/nodeinfo/2.0/')
 
-    // Then we can login
-    cy.visit('/login')
-
     cy.getCookie('csrftoken').then(($cookie) => {
       cy.request({
         method: 'POST',