[FIX] im_livechat: chat bot step sequence tour

This commit fixes the `im_livechat_chatbot_steps_sequence_tour`. When
creating the chat bot steps, we wait for the textarea to be cleared
between each step. However, the selector is wrong: `value()` matches
everything, regardless of the content. This commit fixes the issue by
using `:empty` instead.

follow-up of odoo#217760.
fixes runbot-229755.

closes odoo#218410

X-original-commit: f1280ae
Signed-off-by: Sébastien Theys (seb) <[email protected]>

Author: tsm-odoo

addons/im_livechat/static/tests/tours/im_livechat_chatbot_steps_sequence_tour.js

@@ -29,7 +29,7 @@ function createChatbotSteps(...stepMessages) {
                 },
                 {
                     trigger: ".modal textarea#message_0",
-                    run: () => waitFor(".modal textarea#message_0:value()"),
+                    run: () => waitFor(".modal textarea#message_0:empty"),
                 },
             ])
             .flat(),