chore(envrc): correct paths

.envrc

···
   # we want to track changes here, and reaload the environment
   # we choose these files because they are the ones that are most likely
   # to have made a change that required a shell reaload
-  watch_dir parts/programs
-  watch_file parts/args.nix
+  watch_dir modules/flake/programs
+  watch_file modules/flake/args.nix
 
   # now we want to load the flake environment
   use flake