hardening: Removed next dependency completely

Author: fergusbissetnhs

package.json

@@ -645,7 +645,6 @@
     "jest-axe": "^10.0.0",
     "jsdom": "^27.3.0",
     "mermaid": "^11.12.2",
-    "next": "^16.0.10",
     "nunjucks": "^3.2.4",
     "playwright": "^1.56.1",
     "prettier": "^3.7.4",