chore: add dependency to kerberos

This is necessary for clients that can use kerberos. It's registered
as an optional dependency so clients that can't use kerberos because
they don't have the required system dependencies can still use the
MCP Server w/o kerberos support.

Author: kmruiz

package-lock.json

@@ -119,5 +119,8 @@
   },
   "engines": {
     "node": "^20.19.0 || ^22.12.0 || >= 23.0.0"
+  },
+  "optionalDependencies": {
+    "kerberos": "^2.2.2"
   }
 }