There is an updated pull request by pbui against master on the void-packages repository

https://github.com/pbui/void-packages chromium-widevine
https://github.com/void-linux/void-packages/pull/15810

chromium-widevine: update file structure for 78.0.3904.70
With the update to 78.0.3904.70, chromium now expects additional files
and a new file system layout for the widevine component.

This has been tested with Netflix and Amazon Prime.

A patch file from https://github.com/void-linux/void-packages/pull/15810.patch is attached