ddl,tables: only write the index when it meets partial index condition (#62762)#65700

ti-chi-bot[bot] merged 8 commits into

pingcap:release-8.5-20260116-v8.5.5pingcap/tidb:release-8.5-20260116-v8.5.5from

YangKeao:partial-index-cherry-pick-3YangKeao/tidb:partial-index-cherry-pick-3Copy head branch name to clipboard