When we upgrade from 5.0 to 6.0, we build an index on the config.transactions collection.

By default, index builds have a commit quorum of all voting members. This means that the index build on config.transactions requires all members of the replica set to be up.

This doesn't seem to align with the FCV upgrade being able to proceed with a majority of nodes up.

The purpose of this ticket is to consider whether we want to set the config.transactions index build's commit quorum to a majority rather than all voting members.

See links for related issue which could have been alleviated.