ci: run tests on *cypress* branches (#5298)

.github/workflows/cypress.yml

@@ -24,13 +24,15 @@ jobs:
         with:
           runTests: false
           install-command: yarn install
+          build: yarn build
       - name: Run Cypress tests without a user
         uses: cypress-io/github-action@v4
         with:
-          config: baseUrl=${{env.MAAS_URL}},pageLoadTimeout=100000
+          config: baseUrl="http://localhost:8400/",pageLoadTimeout=100000
           install: false
+          start: yarn start
           spec: "cypress/e2e/no-users/**/*.spec.ts"
-          wait-on: "${{env.MAAS_URL}}/MAAS/r/machines"
+          wait-on: "http://localhost:8400/MAAS/r/machines"
       - name: Create MAAS admin
         run: sudo maas createadmin --username=admin --password=test --email=fake@example.org
       - name: Create MAAS non-admin user