Remove User Content jQuery UI Warning

[NateLevin1]

Summary:

When trying to use the enhanceable_content CSS class to add UI components to user content, an error is printed to the console reading the following upon any user loading the page:

Deprecated use of magic jQueryUI widget markup detected: You're relying on undocumented functionality where Canvas makes jQueryUI widgets out of rich content that has the following class names...

This error message was introduced over 6 years ago and yet these components still work great. Because of this, I think it would be useful to reword or even remove the error message.

Here is the code that causes this behavior:

https://github.com/instructure/canvas-lms/blob/0822f7ff24ef2ee59166afd7cdac72996200413e/ui/shared/enhanced-user-content/jquery/index.js#L94-L103

Steps to reproduce:

1. Go to a rich text editor
2. Go to the HTML view
3. Type the following code:

   <div class="enhanceable_content tabs">
   <ul>
   <li><a href="#tabs-1">Nunc tincidunt</a></li>
   <li><a href="#tabs-2">Proin dolor</a></li>
   </ul>
   <div id="tabs-1">
   Proin
   </div>
   <div id="tabs-2">
   Morbi
   </div>
   </div>

4. Save
5. When you view the content, it will correctly show the tabs.
6. In the console, it logs the error message outlined above.

Expected behavior:

No error message should be printed.

Actual behavior:

The error message is printed.