/usr/share/nvim/runtime/syntax/dns.vim is in neovim-runtime 0.2.2-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | " Vim syntax file
" Language: DNS/BIND Zone File
" This has been replaced by the bindzone syntax
:runtime! syntax/bindzone.vim
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