dm: add LOCK TABLES privilege note for managed MySQL sources (8.5)#22606

alastori wants to merge 2 commits intopingcap:release-8.5pingcap/docs:release-8.5from

alastori:fix/dm-lock-tables-managed-mysql-8.5alastori/tidb-docs:fix/dm-lock-tables-managed-mysql-8.5Copy head branch name to clipboard