Currently we use the DistLock manager to syncronize DDL operations.

Historically DistLocks was required for DDL operations to syncronize with ongoing migrations.

After SERVER-61759 it is not necessary anymore to use DistLock on DDL operations since they all use sharding_ddl_util::stopMigrations to drain and serialize with migrations on a specific collections.

This means that once 6.0 became last LTS we can make DDL operations to start using a node-local-only synchronization mechanism. Moreover by using a local syncronization mechanism that support shared/exclusive mode we will be able to support concurrent DDL operations for the same database.