test: fix run-test-unit.mjs to exit with 1 when test fails

Author: kateinoigakukun

packages/npm-packages/ruby-wasm-wasi/tools/run-test-unit.mjs

@@ -151,7 +151,8 @@ const test = async (instantiate) => {
   await vm.evalAsync(`
     require 'test/unit'
     require_relative '${rootTestFile}'
-    Test::Unit::AutoRunner.run
+    ok = Test::Unit::AutoRunner.run
+    exit(1) unless ok
   `);
 };