doc: update CHANGELOG_V20 about vm fixes
Jest users might need additional changes (probably https://github.com/nodejs/node/pull/49950) to unblock upgrade from v16.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Jest users might need additional changes (probably https://github.com/nodejs/node/pull/49950) to unblock upgrade from v16.