Add 26.2 features (client compatibility, Iceberg translation) to What's New in Cloud#657

kbatuigas wants to merge 4 commits into

mainredpanda-data/cloud-docs:mainfrom

DOC-2312-2311-2290-cloud-26.2-single-sourceredpanda-data/cloud-docs:DOC-2312-2311-2290-cloud-26.2-single-sourceCopy head branch name to clipboard