When using a Cryptomatte node and selecting 2 views in Multi-View,
its output values are doubled. When selecting 3 tripled and so on.
This causes incorrect compositing results for all the views.

The node creates an input operation for each rendered cryptomatte
pass. In Multi-View, passes are rendered for each view but compositor
is executed per view and should only create operations for those
corresponding to the current view being executed. Otherwise duplicated
operations add up later in cryptomatte operation.