fix(updater): accept Korean IME 'ㅛ' as yes in update prompt (#13791)

On the Korean Dubeolsik keyboard layout, the Y key position produces ㅛ
(U+315B) when a Korean IME is active. Since the update confirmation prompt
only matched [yY$'\n'], Korean users who pressed the Y key with the IME on
had their update silently cancelled. Accept ㅛ as an affirmative answer.

tools/check_for_upgrade.sh

@@ -274,11 +274,14 @@ function handle_update() {
 
     # Ask for confirmation and only update on 'y', 'Y' or Enter
     # Otherwise just show a reminder for how to update
+    # ㅛ (U+315B) is the character produced at the Y key position on the Korean
+    # Dubeolsik layout, so it is accepted too to avoid cancelling the update
+    # when a Korean IME is active.
     printf "[oh-my-zsh] Would you like to update? [Y/n] "
     read -r -k 1 option
     [[ "$option" = $'\n' ]] || echo
     case "$option" in
-      [yY$'\n']) update_ohmyzsh ;;
+      [yY$'\n']|$'ㅛ') update_ohmyzsh ;;
       [nN]) update_last_updated_file ;&
       *) echo "[oh-my-zsh] You can update manually by running \`omz update\`" ;;
     esac