Warn about non-mergeable units instead of raising an error#4219

chrishalcrow wants to merge 3 commits intoSpikeInterface:mainSpikeInterface/spikeinterface:mainfrom

chrishalcrow:only-warn-on-sparsity-failurechrishalcrow/spikeinterface:only-warn-on-sparsity-failureCopy head branch name to clipboard