test: exclude test/a11y folder from Vitest to avoid running Playwright tests

Author: tsengwoody

vitest.config.ts

@@ -1,8 +1,9 @@
 /// <reference types="vitest" />
+import { defineConfig, configDefaults } from 'vitest/config';
 import { getViteConfig } from "astro/config";
 import preact from "@preact/preset-vite";
 
-export default getViteConfig({
+export default getViteConfig(defineConfig({
   // needed to ensure react 3rd party libraries work with preact
   plugins: [preact()],
   resolve: {
@@ -12,5 +13,9 @@ export default getViteConfig({
     /* for example, use global to avoid globals imports (describe, test, expect): */
     // globals: true,
     environment: "jsdom",
+    exclude: [
+      ...configDefaults.exclude,
+      'test/a11y/**',
+    ],
   },
-});
+}));