fix: replace NativeDate with Date in IBooking

Use standard Date type instead of removed Mongoose 9 alias.

Co-authored-by: Thomas Ruoff <111471+tomru@users.noreply.github.com>

db/booking.ts

@@ -27,8 +27,8 @@ export interface IBooking {
   destination?: string
   days?: string[]
   calendarEventId?: string
-  createdAt?: NativeDate
+  createdAt?: Date
-  updatedAt?: NativeDate
+  updatedAt?: Date
   toJSON?: () => IBooking
 }