fix: package.json & package-lock.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-BRACES-6838727
- https://snyk.io/vuln/SNYK-JS-MARKDOWNIT-6483324
- https://snyk.io/vuln/SNYK-JS-PUGCODEGEN-7086056
- https://snyk.io/vuln/SNYK-JS-WS-7266574
- https://snyk.io/vuln/SNYK-JS-PATHTOREGEXP-7925106
- https://snyk.io/vuln/SNYK-JS-INFLIGHT-6095116
- https://snyk.io/vuln/SNYK-JS-MICROMATCH-6838728

package.json

@@ -37,7 +37,7 @@
   },
   "homepage": "https://github.com/ministryofjustice/moj-frontend#readme",
   "dependencies": {
-    "@11ty/eleventy": "^2.0.0",
+    "@11ty/eleventy": "^3.0.0",
     "clipboard": "^2.0.8",
     "del": "^7.0.0",
     "esbuild": "^0.23.0",