[steal] steal vulnerable to Prototype Pollution via key variable in babel.js

Prototype pollution vulnerability in function extend in babel.js in stealjs steal via the key variable in babel.js.

References

• https://nvd.nist.gov/vuln/detail/CVE-2022-37266
• https://github.com/stealjs/steal/issues/1535
• https://github.com/stealjs/steal/blob/c9dd1eb19ed3f97aeb93cf9dcea5d68ad5d0ced9/ext/babel.js#L29165
• https://github.com/stealjs/steal/blob/c9dd1eb19ed3f97aeb93cf9dcea5d68ad5d0ced9/ext/babel.js#L29169
• https://github.com/advisories/GHSA-vwhq-pm3r-fjm9