With `plnkrs`, we used to choose a different plnkr mode (normal vs
embedded) based on the size of the screen. This affected the layout of
the plnkr page ("embedded" plnkr mode was usable on small screens, while
"normal" mode wasn't). This is not to be confused with the live-example
mode we use today to determine whether the live-example should be a link
(that open StackBlitz on a new page) or embedded into the document
(using an iframe).
Since we no longer need to change the live-example URL based on the
screen size, there is no need to listen for rezise events on Window. The
necessary properties can be computed once and certain variables are
obsolete.
PR Close#23960
f8c6947205