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

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-NEXT-10176058

Author: snyk-bot

package-lock.json

@@ -299,7 +299,7 @@
     "mdast-util-to-markdown": "2.1.0",
     "mdast-util-to-string": "^4.0.0",
     "morgan": "^1.10.0",
-    "next": "^15.1.5",
+    "next": "^15.1.6",
     "ora": "^8.0.1",
     "parse5": "7.1.2",
     "quick-lru": "7.0.0",