Fixes #37590 - Trigger ready batches on planning finished

Previously we sent the last batch event followed by a regular
TriggerNextBatch event with correct number of batches. The proxy batch
triggering action received the TriggerLastBatch event, set an internal
flag, triggered a single batch and exited, the other event got
discarded. This commit changes the ordering so that the TriggerNextBatch
event is sent out first when planning is done.

(cherry picked from commit 1eb59bb)

app/lib/actions/remote_execution/run_hosts_job.rb

@@ -75,6 +75,7 @@ def trigger_remote_batch
       end
 
       def on_planning_finished
+        trigger_remote_batch
         plan_event(Actions::TriggerProxyBatch::TriggerLastBatch, nil, step_id: input[:trigger_run_step_id])
         super
       end