[3.12] GH-109190: Copyedit 3.12 What's New: Use the ``:file:`` role (GH-109756) (#109806)

GH-109190: Copyedit 3.12 What's New: Use the ``:file:`` role (GH-109756)
(cherry picked from commit 8d365b60bacf0a7edda24eba2d45aba1c2626fbc)

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <hugovk@users.noreply.github.com>