fix(oxlint): ignore fixtures dir for vitest

Author: camc314

apps/oxlint/vitest.config.ts

@@ -1,3 +1,7 @@
-import { defineConfig } from 'vitest/config';
+import { configDefaults, defineConfig } from 'vitest/config';
 
-export default defineConfig({});
+export default defineConfig({
+  test: {
+    exclude: [...configDefaults.exclude, 'fixtures/**'],
+  },
+});