build(deps): Bump dompurify and jspdf (#9)

Bumps [dompurify](https://github.com/cure53/DOMPurify) to 3.3.1 and updates ancestor dependency [jspdf](https://github.com/parallax/jsPDF). These dependencies need to be updated together.


Updates `dompurify` from 2.5.8 to 3.3.1
- [Release notes](https://github.com/cure53/DOMPurify/releases)
- [Commits](cure53/DOMPurify@2.5.8...3.3.1)

Updates `jspdf` from 2.5.2 to 4.0.0
- [Release notes](https://github.com/parallax/jsPDF/releases)
- [Changelog](https://github.com/parallax/jsPDF/blob/master/RELEASE.md)
- [Commits](parallax/jsPDF@v2.5.2...v4.0.0)

---
updated-dependencies:
- dependency-name: dompurify
  dependency-version: 3.3.1
  dependency-type: indirect
- dependency-name: jspdf
  dependency-version: 4.0.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

package-lock.json

@@ -34,7 +34,7 @@
     "@sindresorhus/slugify": "^3.0.0",
     "@x-govuk/govuk-eleventy-plugin": "^7.0.0",
     "govuk-frontend": "5.13.0",
-    "jspdf": "^2.5.2",
+    "jspdf": "^4.0.0",
     "markdown-it": "^14.1.0"
   },
   "devDependencies": {