[JENKINS-70591] Cannot create inline Pipeline job after Ace editor upgrade

[basil]

#653 (comment) was an assertion without evidence, and also an incorrect one — the cause of JENKINS-70591 was #656, not #653. This was determined after a few minutes of bisection. Using the JQuery ready() API gets rid of this bug and is consistent with the code elsewhere in this file which uses JQuery rather than plain JavaScript. Note that I followed the recommended syntax:

jQuery offers several ways to attach a function that will run when the DOM is ready. All of the following syntaxes are equivalent:

• $( handler )
• $( document ).ready( handler )
• $( "document" ).ready( handler )
• $( "img" ).ready( handler )
• $().ready( handler )

As of jQuery 3.0, only the first syntax is recommended; the other syntaxes still work but are deprecated.

The $(function() { syntax did look odd to me, but it is explicitly recommended in the documentation:

Which is equivalent to the recommended way of calling:

$(function() {
  // Handler for .ready() called.
});

To test this, I reproduced the problem described in JENKINS-70591 and verified the problem no longer occurred after this PR. I also repeated the testing done in #656 and #653.