chore(deps): update devdependency knip to v6

Author: renovate[bot]

package.json

@@ -129,7 +129,7 @@
 		"discord-api-types": "0.38.42",
 		"eslint": "9.39.4",
 		"eslint-plugin-regexp": "3.1.0",
-		"knip": "5.88.1",
+		"knip": "6.12.1",
 		"prisma": "7.7.0",
 		"prisma-json-types-generator": "5.0.0",
 		"skilld": "1.6.2",