Don't autowire non-nix files

[srid]

Discussed in https://github.com/srid/nixos-unified/discussions/98

^{Originally posted by shivaraj-bh January 17, 2025} Is this because of autowiring?

This occurred while I was setting up nixos-unified-template on a colleagues mac. I was editing the shell.nix module using vim and vim created a swp file.