After T190015: Create separate user group for editing sitewide CSS/JavaScript that does not include administrators by default each user can still edit js pages in their own userspace.
As an admin, I am also able to delete js pages in my own userspace.
But I cannot edit or delete this page: https://el.wikipedia.org/w/index.php?title=User:Geraki/schoolip.js&redirect=no
I also tried to change the page content model (in chance it would let me delete it as wiki page) but there is no such option in the relevant info page.