fix: update todo.sh alias so it stopped showing as not found

.aliases

@@ -1,5 +1,7 @@
 # ~/.aliases
 
+TODO_BIN=$(which todo.sh)
+
 alias grep='grep --color=auto'
 alias fgrep='fgrep --color=auto'
 alias egrep='egrep --color=auto'
@@ -36,7 +38,7 @@ alias cat='bat --paging=never --style=plain'
 alias pcat='bat --paging=auto --style=auto'
 
 # todo.txt
-alias t='$(which todo.sh) -a'
+alias t='$TODO_BIN -a'
 
 # Arch
 alias yay='nocorrect yay --color=auto'