Bump xmldom from 0.1.22 to 0.6.0

Bumps [xmldom](https://github.com/xmldom/xmldom) from 0.1.22 to 0.6.0.
- [Release notes](https://github.com/xmldom/xmldom/releases)
- [Changelog](https://github.com/xmldom/xmldom/blob/master/CHANGELOG.md)
- [Commits](https://github.com/xmldom/xmldom/commits/0.6.0)

---
updated-dependencies:
- dependency-name: xmldom
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

npm-shrinkwrap.json

@@ -19,7 +19,7 @@
     "stylelint": "8.0.0",
     "stylelint-checkstyle-formatter": "0.1.0",
     "stylelint-csstree-validator": "1.1.1",
-    "xmldom": "0.1.22",
+    "xmldom": "0.6.0",
     "xpath": "0.0.23"
   },
   "engines": {