feat: add phase 4 bun_test bootstrap

Co-authored-by: Eriyc <50216491+Eriyc@users.noreply.github.com>

tests/bun_test_test/failing.test.ts

@@ -0,0 +1,5 @@
+import { expect, test } from "bun:test";
+
+test("failing suite", () => {
+  expect(1 + 1).toBe(3);
+});