Bump xml2js and vscode-extension-tester

Bumps [xml2js](https://github.com/Leonidas-from-XIV/node-xml2js) to 0.5.0 and updates ancestor dependency [vscode-extension-tester](https://github.com/redhat-developer/vscode-extension-tester). These dependencies need to be updated together.


Updates `xml2js` from 0.4.23 to 0.5.0
- [Release notes](https://github.com/Leonidas-from-XIV/node-xml2js/releases)
- [Commits](https://github.com/Leonidas-from-XIV/node-xml2js/commits/0.5.0)

Updates `vscode-extension-tester` from 5.0.0 to 5.5.3
- [Release notes](https://github.com/redhat-developer/vscode-extension-tester/releases)
- [Changelog](https://github.com/redhat-developer/vscode-extension-tester/blob/main/CHANGELOG.md)
- [Commits](redhat-developer/vscode-extension-tester@v5.0.0...v5.5.3)

---
updated-dependencies:
- dependency-name: xml2js
  dependency-type: indirect
- dependency-name: vscode-extension-tester
  dependency-type: direct:development
...

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Author: dependabot[bot]