chore: update cypress config (#9142)

Author: tenphi

packages/cubejs-testing/cypress.config.ts

@@ -19,4 +19,7 @@ export default defineConfig({
     baseUrl: 'http://localhost:3080',
     specPattern: 'cypress/e2e/**/*.{js,jsx,ts,tsx}',
   },
-})
+  // set optimal values for the number of tests kept in memory
+  numTestsKeptInMemory: 10,
+  experimentalMemoryManagement: true,
+});