Bump xml2js, @azure/keyvault-keys and @azure/ms-rest-js

Removes [xml2js](https://github.com/Leonidas-from-XIV/node-xml2js). It's no longer used after updating ancestor dependencies [xml2js](https://github.com/Leonidas-from-XIV/node-xml2js), [@azure/keyvault-keys](https://github.com/Azure/azure-sdk-for-js) and [@azure/ms-rest-js](https://github.com/Azure/ms-rest-js). These dependencies need to be updated together.


Removes `xml2js`

Updates `@azure/keyvault-keys` from 4.3.0 to 4.7.0
- [Release notes](https://github.com/Azure/azure-sdk-for-js/releases)
- [Changelog](https://github.com/Azure/azure-sdk-for-js/blob/main/documentation/Changelog-for-next-generation.md)
- [Commits](https://github.com/Azure/azure-sdk-for-js/compare/@azure/keyvault-keys_4.3.0...@azure/keyvault-keys_4.7.0)

Updates `@azure/ms-rest-js` from 2.5.3 to 2.6.6
- [Release notes](https://github.com/Azure/ms-rest-js/releases)
- [Changelog](https://github.com/Azure/ms-rest-js/blob/master/Changelog.md)
- [Commits](https://github.com/Azure/ms-rest-js/commits)

---
updated-dependencies:
- dependency-name: xml2js
  dependency-type: indirect
- dependency-name: "@azure/keyvault-keys"
  dependency-type: indirect
- dependency-name: "@azure/ms-rest-js"
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>