fix: reuse table items when updating sync results

sync_video_test.py

@@ -877,13 +877,15 @@ class VideoSyncWindow:
             items = [row["method"], f"{row['lag_frames']:.3f}", f"{row['lag_sec']:.6f}",
                      f"{row['peak']:.4f}", f"{row['agree_med_frames']:+.2f}"]
             for j, txt in enumerate(items):
-                it = self.table.item(i, j) or self.Qt[0].QTableWidgetItem()
+                it = self.table.item(i, j)
+                if it is None:
+                    it = self.Qt[0].QTableWidgetItem()
+                    self.table.setItem(i, j, it)
                 it.setText(txt)
                 if m == self.active:
                     it.setBackground(self.Qt[2].QColor(60, 120, 200).darker(150))
                 if not self.enabled[m]:
                     it.setForeground(self.Qt[2].QColor(110, 110, 110))
-                self.table.setItem(i, j, it)
 
     def update_zones(self):
         ctx = self.ctx