revert(shell): move iris integration to the iris branch

Reverts 43dfe48, 0692ae3, e0cdcd6 and the cable-description half of
098da70 (the star-prompt stats stay). master returns to the pre-iris
shell setup: atuin in fish/zsh/bash, the down -> pj binding with
PJ_QUIET, and the fish/zsh key bindings as they were. The iris work
lives on the `iris` branch.

dot_config/fish/functions/_gho_bind.fish

@@ -1,8 +1,6 @@
 function _gho_bind --description 'ctrl-o: gho (tv --inline), then redraw the prompt in the right place'
     set -l before $PWD
-    _iris_busy start
     gho
-    _iris_busy stop
     if test "$PWD" = "$before"
         # Cancelled (or the nvim action ran): tv --inline left the cursor on
         # the line below the prompt; step back so repaint redraws in place.