That file is the combination of all your site’s JS files Steve and if you have a lot of JavaScript then indeed the aggregated JS-file is likely to be mentioned as having long tasks/ long execution time.
Although it won’t help with the fact you have a lot of JS, it might help NOT to aggregate the JS, configuring AO instead to “don’t aggregate but defer” + “also defer inline JS” and possibly removing most or even all of the exclusions?
The best solution however will be to make the site less dependent on JavaScript 🙂