bump for next beta

actually this is the right PR number

bump beta channel too

changelog for hotfix release

Merge pull request desktop#5019 from desktop/them-release-notes

release notes for next prod ship

bump for one final beta

Merge pull request desktop#5006 from desktop/the-final-countdown-slas…

…h-beta

probably the last beta before 1.2.4 ships

Merge pull request desktop#4980 from desktop/a-new-beta-build

cut a new beta build

cut another beta to address webpack issue

version bump