523e5711

Don’t force Nix in direnv for non-Nix users

Direnv doesn’t currently allow ignoring a file. If you haven’t allowed it, it
will complain that there’s an un-allowed file. This makes it possible for a
contributor to allow it, but not get complaints that they don’t have Nix
installed or flakes enabled.
Time to start 0s
Time from start to finish 1m01s
Time to finish 1m02s
Total worker time 57s