[BUG] Update the currently supported release of Chef Backend

[tas50]

General details

Link to page and section that needs to be updated:

https://docs.chef.io/versions/#supported-commercial-distributions

Product

[ ] Chef Automate
[ ] Chef Habitat
[ ] Chef Infra Client
[ ] Chef Infra Server
[ ] Chef InSpec
[ ] Other________________

Describe the update that needs to be made. Be as specific as possible:

The currently supported Free release of Supermarket is 4.x. Supermarket less than 4 needs to be listed as EOL 2021-12-31