puppet agent catalogs are never hitting catalog cache

Now that we have some basic metrics about puppet agent runs, we can see that none of the agents are ever getting their catalog from cache:

https://prometheus.torproject.org/classic/graph?g0.range_input=7d&g0.expr=sum(puppet_cache_catalog_status)%20by%20(state)&g0.tab=0

(91 is the current total number of puppet agents)

It could be interesting to take a look into how puppet agent catalog caching is implemented / enabled and how it could impact performance for our puppet server.