test: use tmpdir.refresh() in test-esm-json.mjs

Use `tmpdir.refresh()` in `test/es-module/test-esm-json.mjs` so that
the temporary directory is removed when the test exits.

Author: lpinca

test/es-module/test-esm-json.mjs

@@ -9,6 +9,8 @@ import * as tmpdir from '../common/tmpdir.js';
 
 import secret from '../fixtures/experimental.json' with { type: 'json' };
 
+tmpdir.refresh();
+
 describe('ESM: importing JSON', () => {
   it('should load JSON', () => {
     assert.strictEqual(secret.ofLife, 42);