Bump dompurify from 2.2.9 to 2.5.6

Bumps [dompurify](https://github.com/cure53/DOMPurify) from 2.2.9 to 2.5.6.
- [Release notes](https://github.com/cure53/DOMPurify/releases)
- [Commits](https://github.com/cure53/DOMPurify/compare/2.2.9...2.5.6)

---
updated-dependencies:
- dependency-name: dompurify
  dependency-type: indirect
...

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

package-lock.json

@@ -563,9 +563,9 @@
 			}
 		},
 		"dompurify": {
-			"version": "2.2.9",
-			"resolved": "https://registry.npmjs.org/dompurify/-/dompurify-2.2.9.tgz",
-			"integrity": "sha512-+9MqacuigMIZ+1+EwoEltogyWGFTJZWU3258Rupxs+2CGs4H914G9er6pZbsme/bvb5L67o2rade9n21e4RW/w==",
+			"version": "2.5.6",
+			"resolved": "https://registry.npmjs.org/dompurify/-/dompurify-2.5.6.tgz",
+			"integrity": "sha512-zUTaUBO8pY4+iJMPE1B9XlO2tXVYIcEA4SNGtvDELzTSCQO7RzH+j7S180BmhmJId78lqGU2z19vgVx2Sxs/PQ==",
 			"dev": true
 		},
 		"dot-prop": {