Apart from removing these libraries because the Flash Player was deprecated
in 2017 and officially discontinued on 31 December 2020, the rtmp and useflash
settings have been removed too (they make no sense anymore).

Upgrade videojs media player to version 7.6.5 as well
as a general update this adds MPEG-DASH and HLS playlist
support to the Video.JS media player.

Upgrade Video.JS to 7.5.5
Upgrade videojs-youtube plugin to 2.6.0
Upgrade videojs-flash plugin to 2.2.2

Added additional AMD modules for bootstrapping the DOM
window and document objects to Video.JS in line with the
updates made to Video.JS.

Dan Poltawski authored Jan 11, 2017 and Marina Glancy committed Jan 12, 2017

The videojs javascript is over 1MB of javascript which we don't need to
load on every page, now that we only require it demand, the js can be
lazily loaded when its needed, which keeps the first.js smaller and more
likely to stay in browser cache.