Should webgl validation be run as a step in the release process?

Running tests with webgl validation used to be a part of the [release process](https://github.com/CesiumGS/cesium/wiki/Release-Guide), but due to [webgl validation taking significantly longer to run](https://github.com/CesiumGS/cesium/issues/6570) and [inconsistent results across browsers](https://github.com/CesiumGS/cesium/issues/3888), it had not been enforced. Is it worth looking into improving performance and including this as part of the release process once again?

Start with the Release Guide and the linked issues #6570 and #3888 to understand the current webgl validation process, its runtime cost, and browser inconsistencies. Done means establishing whether validation can be made reliable and fast enough to be enforced again during releases, with the release-process change clearly documented.

Written by the indexing model from the issue text.