fix: failing github actions by updating test262

Fixes the `test:test262` step of the Github Action flow.

Should fix: #27

- updating the `test262` dependency
- updating the files whitelist in `run_test262.js`

- This was preventing the Github Actions to succeed
- Therefore preventing Yarn to public the new tag release
- Therefore preventing Webpack to update to any version above 1.9.0

```
@alexandrenicol ➜ /workspaces/acorn-import-attributes (fix-test-262) $ npm run test:test262

> acorn-import-attributes@1.9.3 test:test262
> node run_test262.js

Testing complete.
Summary:
 ✔ 71 valid programs parsed without error
 ✔ 5 invalid programs produced a parsing error
 ✔ 10 invalid programs did not produce a parsing error (and allowed by the whitelist file)
 ✔ 111 valid programs produced a parsing error (and allowed by the whitelist file)
 ✔ 97695 programs were skipped
```

Which is similar to what it was when first introduced in #13 (comment)

package.json

@@ -29,7 +29,7 @@
     "acorn": "^8.4.1",
     "chai": "^4.3.4",
     "mocha": "^9.1.0",
-    "test262": "https://github.com/tc39/test262#47ab262658cd97ae35c9a537808cac18fa4ab567",
+    "test262": "https://github.com/tc39/test262#39168e26c8b17782994388f8a7b59a8173f5de83",
     "test262-parser-runner": "^0.5.0"
   },
   "peerDependencies": {