chore: move govuk-frontend to peerDependencies; keep in devDependencies for local development

Author: alexluckett

package.json

@@ -115,7 +115,6 @@
     "expr-eval-fork": "^3.0.3",
     "geodesy": "^2.4.0",
     "google-libphonenumber": "^3.2.44",
-    "govuk-frontend": "^6.2.0",
     "hapi-pino": "^13.0.0",
     "hapi-pulse": "^3.0.1",
     "highlight.js": "^11.11.1",
@@ -203,6 +202,10 @@
     "typescript-eslint": "^8.56.1",
     "webpack": "^5.107.2",
     "webpack-assets-manifest": "^6.5.2",
-    "webpack-cli": "^7.0.3"
+    "webpack-cli": "^7.0.3",
+    "govuk-frontend": "^6.2.0"
+  },
+  "peerDependencies": {
+    "govuk-frontend": "^6.0.0"
   }
 }