Script Loader: Restore correct versions for Masonry and imagesLoaded.

These libraries were previously updated in [48038], but some changes were accidentally reverted in [48267].

Props kebbet.
See #50526.
Built from https://develop.svn.wordpress.org/trunk@48276


git-svn-id: https://core.svn.wordpress.org/trunk@48045 1a063a9b-81f0-0310-95a4-ce76da25c4cd