Suppress now-visible LSan leak and have IM engine shut down any remai…

…ning subscriptions.

scripts/tests/chiptest/lsan-mac-suppressions.txt

@@ -33,3 +33,6 @@ leak:[CHIPToolKeypair signMessageECDSA_RAW:]
 # TODO: Figure out how we are managing to leak NSData while using ARC, though
 # this may just be a leak deep inside the CFPreferences stuff somewhere.
 leak:[CHIPToolPersistentStorageDelegate storageDataForKey:]
+
+# TODO: https://github.com/project-chip/connectedhomeip/issues/22333
+leak:[MTRBaseCluster* subscribeAttribute*WithMinInterval:maxInterval:params:subscriptionEstablished:reportHandler:]

src/app/InteractionModelEngine.cpp

@@ -98,6 +98,11 @@ void InteractionModelEngine::Shutdown()
 
  mReadHandlers.ReleaseAll();
 
+ // Shut down any subscription clients that are still around. They won't be
+ // able to work after this point anyway, since we're about to drop our refs
+ // to them.
+ ShutdownAllSubscriptions();
+
  //
  // We hold weak references to ReadClient objects. The application ultimately
  // actually owns them, so it's on them to eventually shut them down and free them