SERVER-92364 added a temporary workaround in checkMetadataConsistency's cross-shard index consistency pipeline (checkIndexesConsistencyAcrossShards in metadata_consistency_util.cpp) to tolerate expireAfterSeconds being stored as different numeric BSON types across shards in mixed-version clusters.

The workaround casts all numeric expireAfterSeconds values to long before comparison when FCV < 9.0. Once FCV reaches 9.0, SERVER-120253 ensures all on-disk values are normalized to integer, so any remaining type mismatch is a genuine inconsistency.

When 9.0 becomes last LTS, this workaround is no longer needed and should be removed:

• In metadata_consistency_util.cpp: remove the $map/$cond/$toLong transformation in the $group stage of the pipeline, reverting specs back to $push: {$objectToArray: {$ifNull: ['\$indexDoc.spec', {}]}}.
• Remove the fcvSnapshot / tolerateExpireAfterSecondsTypeMismatch variable and the aggRequest.setLet(...) call.
• Remove the TODO comments referencing this ticket.