Deprecate diff_matched output in DiffMatchedTractCatalog

This task was originally created to output differences between matched sources (objectTable_tract and truth_summary) to a table, which was then read by faro and used to dispatch metrics. Metric generation has since been migrated to analysis_tools (which only needs the cat_matched matched table output), so while this part of the task works, it is mostly just a maintenance burden and I am unaware of anyone still looking at the matched difference table output.