Deleted books/chapters/pages can cause failure of notification preferences view #4499
Description
Describe the Bug
Created a book of articles enabled subscription to notifications. Deleted the book.
Steps to Reproduce
1.Created a book
2.Create a page
3. Enabled subscription to notifications.
4. 4 Deleted the book
6. I go to the settings and get an error
Expected Behaviour
When deleting a book, automatic deletion of notifications
Screenshots or Additional Context
Browser Details
No response
Exact BookStack Version
BookStack v23.08
PHP Version
No response
Hosting Environment
Docker