As part of integrating with Skia Gold (#33688), golden file tests/files will no longer need their version number incorporated into their names. While transitioning to Skia Gold, the original system via the flutter/goldens repository is to remain in place.
Establishing the new testing environment free of irrelevant former version numbers makes for a better user experience as well, so versioning needs to be split out, while still being able to reference flutter/goldens.

• Don't forget to make any necessary updates to the wiki as a result: https://github.com/flutter/flutter/wiki/Writing-a-golden-file-test-for-package:flutter