Page-Specific template in Site Editor detaches itself from the page when page slug is updated.

[talhaqureshi]

If the page slug is updated, the Page-Specific template that was created within the Appearance > Editor section will detach itself from the page.

Steps to Reproduce

1. Create a new page.
   
2. Create a new page-specific template within Appearance > Editor specifically for the page you created.
   
3. Change the slug (URL) of the newly created page.
   
4. Upon changing the slug, you will notice that the page-specific template becomes detached from the page, meaning it is no longer associated with it.