lorri needs to be told which Nix shell definition to use

Dependencies

• [2] G734WNM6 flake.nix: use crate2nix
• [3] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• replacement in shell.nix at line 5
  [2.248496]→[2.248496:248523](∅→∅)
  − { src = ./.; }).shellNix
  [2.248496]
  + { src = ./.; }).shellNix.default