Revert "Add tmux-which-key plugin"

This reverts commit adbae6f0ad.

.config/tmux/tmux.conf

@@ -31,7 +31,6 @@ set -g history-file ~/.local/state/tmux_history
 set-option -g @plugin 'tmux-plugins/tpm'
 set-option -g @plugin 'noscript/tmux-mighty-scroll'
 set-option -g @mighty-scroll-by-line 'man less pager fzf emacs emacsclient'
-set-option -g @plugin 'alexwforsythe/tmux-which-key'
 
 # install/update tpm
 if-shell "test ! -d  ~/.config/tmux/plugins/tpm" {