We use jQuery 1.12.4 on our site - the latest 1.x version from before they stopped supporting it. PCI compliance scans are flagging this as being vulnerable and out of date, because there are some security patches in the latest 3.x versions (e.g. https://blog.jquery.com/2020/04/10/jquery-3-5-0-released/).
We can't simply move to 3.x because there are many breaking changes and incompatibilities; it would be an enormous undertaking. Luckily, they provide an example of how to back-port the security patches into 1.x here: https://github.com/DanielRuf/snyk-js-jquery-565129
This is great for the un-minified file, but doesn't help on the minified one we need for production. I've never done it before, but I was going to try to follow their advice and build and minify it myself. But I can't even find the source code for jQuery 1.x! I pulled down the code from https://github.com/jquery/jquery and built it, but it's version 4.x.
Is there anywhere I can get the minified version of jQuery 1.12.4 with the latest security patches applied?
Or, does someone at least know where the source code for jQuery 1.x is?