nix-profile.fish: Add local state dir bin to $PATH

It seems reasonable to add both `$HOME/.profile/bin` and
`@localstatedir@/nix/profiles/default/bin` to `$PATH` for both user
local and daemon based nix execution.  Nix daemon execution mode does
not affect these path.

Author: ilya-bobyr

scripts/nix-profile.fish.in

@@ -69,6 +69,7 @@ if set --query MANPATH
     set --export --prepend --path MANPATH "$NIX_LINK/share/man"
 end
 
+add_path "@localstatedir@/nix/profiles/default/bin"
 add_path "$NIX_LINK/bin"
 
 # Cleanup