alacritty: remove Ctrl-Backspace workaround

i don't remember why it is there, but it conflicts with zsh bindkey's
vi-mode

.config/alacritty/alacritty.yml

@@ -53,7 +53,6 @@ mouse:
   hide_when_typing: true
 
 key_bindings:
-  - { key: Back,      mods: Control,                   chars: "\x1b\x7f"      }
   - { key: Semicolon, mods: Control|Shift,             chars: "\e;"           }
   - { key: PageUp,    mods: Shift,         mode: ~Alt, action: ScrollPageUp   }
   - { key: PageDown,  mods: Shift,         mode: ~Alt, action: ScrollPageDown }