Merge pull request #55888 from myoungwon/wip-seastore-cleanup-is-stable-fix

crimson/os/seastore: cleanup and use LBAMapping::is_stable()

Reviewed-by: Yingxin Cheng <yingxin.cheng@intel.com>

diff --cc src/crimson/os/seastore/transaction_manager.h
Simple merge