Use Nise 6 with legacyRoutes flag enabled

This should be disabled in a future Sinon version by default.

Author: fatso83

package-lock.json

@@ -78,7 +78,7 @@
     "@sinonjs/fake-timers": "^11.2.2",
     "@sinonjs/samsam": "^8.0.0",
     "diff": "^5.2.0",
-    "nise": "^5.1.9",
+    "nise": "^6.0.0",
     "supports-color": "^7"
   },
   "devDependencies": {