[jQuery 4] ajax.js and jquery.form.js use deprecated function $.parseJSON()

I think, a lot of "old" jQuery code could / should be moved to vanilla to prevent most of those deprecations.

@Tart0 see #3238306: [META] Where possible, refactor existing jQuery uses to vanillaJS to reduce jQuery footprint → , we need help in many child issues to make that switch.

The only other place $.parseJSON appears is in core/misc/jquery.form.js, I think we should fix it there too while we are here?

@longwave wasn't aware of that meta issue, i'll give a look and provide as much as I can, thanks !

Confirmed all instances of $.parseJSON have been replaced.

Committed a605d77 and pushed to 11.x. Thanks!

There is no rule for that in eslint-plugin-jquery so leaving as-is

nod_ → closed merge request !7093

Automatically closed - issue fixed for 2 weeks with no activity.