MKS H43 fixup (#21267)

Co-authored-by: makerbase <4164049@qq.com>
Co-authored-by: MKS-Sean <56996910+MKS-Sean@users.noreply.github.com>
Co-authored-by: Scott Lahteine <github@thinkyhead.com>

Marlin/src/gcode/queue.cpp

@@ -610,6 +610,14 @@ void GCodeQueue::get_available_commands() {
   TERN_(SDSUPPORT, get_sdcard_commands());
 }
 
+/**
+ * Run the entire queue in-place. Blocks SD completion/abort until complete.
+ */
+void GCodeQueue::exhaust() {
+  while (ring_buffer.occupied()) advance();
+  planner.synchronize();
+}
+
 /**
  * Get the next command in the queue, optionally log it to SD, then dispatch it
  */