Replace memcpy with structure assignment in apply_worker_get_progress

Use direct structure assignment instead of memcpy for copying
SpockApplyProgress. This is more idiomatic, type-safe, and resolves
static analyzer warnings about buffer size validation.

The compiler generates identical code while providing compile-time
type checking and better code clarity.

Author: danolivo

src/spock_group.c

@@ -407,9 +407,7 @@ apply_worker_get_progress(void)
 	if (MyApplyWorker && MyApplyWorker->apply_group)
 	{
 		LWLockAcquire(SpockCtx->apply_group_master_lock, LW_SHARED);
-
-		memcpy(&sap, &MyApplyWorker->apply_group->progress,
-			   sizeof(SpockApplyProgress));
+		sap = MyApplyWorker->apply_group->progress;
 		LWLockRelease(SpockCtx->apply_group_master_lock);
 	}
 	else