Update dependency knip to v6.12.0

Author: renovate[bot]

package.json

@@ -36,7 +36,7 @@
     "@types/node": "24.12.2",
     "eslint": "8.57.1",
     "eslint-plugin-ghost": "3.5.0",
-    "knip": "6.11.0",
+    "knip": "6.12.0",
     "nx": "22.7.1",
     "tsx": "4.21.0",
     "typescript": "6.0.3"