SERVER-78611 added an isShardedColl method to cluster_commands_helpers, which queries the configsvr metadata.

This method has very deceiving stability guarantees and will very likely be misused.
The original usage on collmod_coordinator was right in using it because it does have stability guarantees due to it being a ddl coordinator that is holding the DDL lock.
The new usages on cluster_* commands do not have that stability. Also, given that those are router commands, which operate on a routing table, it is not necessary to use isShardedColl to figure out if the collection was sharded – the routing table itself already has that information.