chore(deps): update dependency posthog-node to v5.8.1

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

bun.lock

@@ -40,7 +40,7 @@
     "lucide-react": "0.542.0",
     "next": "15.5.2",
     "posthog-js": "1.261.0",
-    "posthog-node": "5.8.0",
+    "posthog-node": "5.8.1",
     "prettier": "3.6.2",
     "react": "19.1.1",
     "react-dom": "19.1.1",