/usr/lib/ghc-doc/hoogle/persistent-template.txt is in libghc-persistent-template-doc 1.2.0.4-1build3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-persistent-template-doc/html/persistent-template.txt