Plyr (video player) needs upgrading

[mr-c]

Judging by the git history, I'm guessing we have version v3.6.3 of Plyr

Version v3.7.3 is the latest, but I don't see any instructions on how to go from the releases to what we have in https://github.com/common-workflow-language/cwl-website/tree/main/content/assets/plyr

We have several security alerts related to the old version of Plyr.

[mr-c]

Plyr is deprecated and vidstack is it's successor

sampotts/plyr#2737

https://www.vidstack.io/docs/player/getting-started/installation/cdn?styling=default-layout&provider=video

[mr-c]

Vidstack has a Plyr compatability mode
sampotts/plyr#2408 (comment)