Bump dompurify from 3.0.5 to 3.0.9 (#833)

Bumps [dompurify](https://github.com/cure53/DOMPurify) from 3.0.5 to 3.0.9.
- [Release notes](https://github.com/cure53/DOMPurify/releases)
- [Commits](cure53/DOMPurify@3.0.5...3.0.9)

---
updated-dependencies:
- dependency-name: dompurify
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -41,7 +41,7 @@
     "classnames": "^2.3.1",
     "copy-webpack-plugin": "^12.0.2",
     "css-loader": "^0.28.5",
-    "dompurify": "^3.0.3",
+    "dompurify": "^3.0.9",
     "expect": "^21.1.0",
     "extract-text-webpack-plugin": "3.0.2",
     "file-loader": "^6.2.0",