Can we automatically run the full test suite with polyfill combinations before a release?

[romainmenke]

Perhaps we should have a full polyfill combination run happen when we make a release branch? I guess it'd require either detecting that package.json.version had changed or we would need to use a special branch name which we configured a GitHub workflow to run on

Originally posted by @JakeChampion in https://github.com/Financial-Times/polyfill-library/pull/1213#pullrequestreview-1062639907