[Dispatch] Two fixes for CollapseDimensionsPass

[IanWood1]

#19113 uncovered some problems with the logic in this pass.

Fixes two problems:

1. If a consumer cannot be collapsed, producers can only collapse dimensions not touched by the consumer
2. When updating which consumer loops can be collapsed, the reassociation of the producer must be taken into account since its possible they are not all contiguous (e.g. a transpose on an input). This is the same logic as in updateFromConsumer