Fixed clicking global Duo Chat button after dismissed callout

What does this MR do and why?

The MR fixes clicking on the global Duo Chat button when the callout shouldn't be rendered. This is different from dismissing the callout and clicking the button in the same session - make sure to follow the instructions below for testing.

Screenshots or screen recordings

Before	After
callout-error	callout-fixed

How to set up and validate locally

1. Set up GitLab Duo Chat
2. Enable the global GitLab Duo button:

# rails c

[1] pry(main)> Feature.enable(:tanuki_bot_breadcrumbs_entry_point)

3. Load any page in the local GDK. If you haven't dismissed the global button's callout previously, you should see something like this:

4. Dismiss the callout clicking anywhere on the page outside of the callout itself.
5. Reload the page - you should see the button, but not callout.
6. Click the global Duo Chat button. Duo Chat should be opened and the Cannot read properties of undefined (reading '$emit') error shouldn't be thrown.