Bump dompurify and @types/dompurify in /app

Bumps [dompurify](https://github.com/cure53/DOMPurify) and [@types/dompurify](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/dompurify). These dependencies needed to be updated together.

Updates `dompurify` from 3.1.7 to 3.2.1
- [Release notes](https://github.com/cure53/DOMPurify/releases)
- [Commits](https://github.com/cure53/DOMPurify/compare/3.1.7...3.2.1)

Updates `@types/dompurify` from 3.0.5 to 3.2.0
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/dompurify)

---
updated-dependencies:
- dependency-name: dompurify
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: "@types/dompurify"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

app/package.json

@@ -17,8 +17,8 @@
 	},
 	"type": "module",
 	"dependencies": {
-		"@types/dompurify": "^3.0.2",
-		"dompurify": "^3.1.7",
+		"@types/dompurify": "^3.2.0",
+		"dompurify": "^3.2.1",
 		"marked": "^15.0.2"
 	}
 }