test: remove CSS import from set-up file

Author: metonym

tests/setup-tests.ts

@@ -1,7 +1,6 @@
 /// <reference types="vitest/globals" />
 import "@testing-library/jest-dom/vitest";
 import { userEvent } from "@testing-library/user-event";
-import "../css/all.css";
 
 // Mock scrollIntoView since it's not implemented in JSDOM
 Element.prototype.scrollIntoView = vi.fn();