/usr/lib/ghc-doc/hoogle/libghc-agda-doc.txt is in libghc-agda-doc 2.4.2.5-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/ghc-doc/hoogle/../../../share/doc/libghc-agda-doc/html/Agda.txt