RHEL 8.2 is only supported with Couchbase Server 6.6.0 onwards

We should add a footnote in the Supported Platforms page for 6.5.x indicating that existing versions of Couchbase Server 6.5.x (latest: 6.5.1) are not compatible with RHEL 8.2 (Oopta).

We should do this sooner rather than later since we mention Cent OS 8.x as a supported platform for the 6.5.x releases in Development, Testing, and Production environments and customers are likely to run into this issue.

We should optionally also mention in the Release Notes of 6.5.x that RHEL 8.2 (Oopta) is incompatible with existing versions of Couchbase Server.

Support for RHEL 8.2 has been added for Couchbase Server version 6.6.0 onward. This does not affect other RPM based distros (Amazon Linux and Suse Linux), just CentOS 8.