New Features
* #3547500 Change Content-Type to application/json for the application firewall be happy.

Tasks
* #3572580 Turn off next major
* #3569557 Add review instructions to documentation
* #3570317 Update General Contribution Guideline

Bugs
* #3570952 js_build is run in every branch

Contributors:
rondev, marcus_johansson, arianraeesi, ahmad khader, a.dmitriiev, nikro, scott_euser, breidert, danrod, thamas