fix(deps): update dependency sitemap to v6 (#8198)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

install/package.json

@@ -110,7 +110,7 @@
         "semver": "^7.0.0",
         "serve-favicon": "^2.4.5",
         "sharp": "0.25.1",
-        "sitemap": "^5.0.0",
+        "sitemap": "^6.0.0",
         "socket.io": "2.3.0",
         "socket.io-adapter-cluster": "^1.0.1",
         "socket.io-adapter-mongo": "^2.0.4",