message_containers required feature flag

### Describe the bug We upgraded from a previous install to 3.13.7 and then attempted to upgrade to 4.2.2. This failed because we did not have message_containers feature flag enabled, even though it is not listed as required. ### Reproduction steps 1. 3.13.7 cluster with message_containers disabled 2. attempt to upgrade node to 4.2.2 3. upgrade fails because required feature flag message_containers is not enabled. ... ### Expected behavior website documentation show show message_containers as required.. Thank you! ### Additional context _No response_