As reported in #37699, the size of the main angular.io bundle sometimes
ends up bigger than expected on CI. This usually goes away after
rerunning the job a couple of times.
It is unclear what is causing this. In order to help debug the issue,
this commit stores the JS files that are checked as part of the aio
payload-size check as CI artifacts, where they can be retrieved from and
inspected.
PR Close#37703
George Kalpakas