Add Positional only arguments forward slash (/) to sorted() function in Built-in Functions document (GH-30113)

sorted() function is missing forward slash (/) in Built-in Functions documentation page.

Automerge-Triggered-By: GH:asvetlov
(cherry picked from commit f025ae63dccf96c4a1d781a6438bd9ed1502f0a1)

Co-authored-by: Vivek Vashist <vivekvashist@gmail.com>