The heat of your rendering process
should kill your botulism organisms if present, so the risk would lie in recontaminating the lard while putting it in the jars. If you hot-packed your jars before the lard got cool
enough for botulism organisms to survive, I think even that slight risk would go away.
It's worth remembering, too, that cooking destroys the botulism
toxin. Since most people cook with lard instead of eating it straight out of the jar cold, that's another factor that diminishes the risk. (It's a different story for canned meats, which are more likely to be eaten without further cooking.)
I got curious and did some Google searching. In the first few pages of results I didn't find any confirmed references to people suffering botulism poisoning from eating lard, although I found many concerned do-it-yourselfers repeating (conflicting and vague) inherited legends and received wisdoms on the subject.