refactor: optimize overlap detection logic in block_pre_proc.py for efficiency

mineru/utils/block_pre_proc.py

@@ -213,9 +213,10 @@ def remove_overlaps_min_blocks(all_bboxes):
     #  重叠block，小的不能直接删除，需要和大的那个合并成一个更大的。
     #  删除重叠blocks中较小的那些
     need_remove = []
-    for block1 in all_bboxes:
-        for block2 in all_bboxes:
-            if block1 != block2:
+    for i in range(len(all_bboxes)):
+        for j in range(i + 1, len(all_bboxes)):
+            block1 = all_bboxes[i]
+            block2 = all_bboxes[j]
             block1_bbox = block1[:4]
             block2_bbox = block2[:4]
             overlap_box = get_minbox_if_overlap_by_ratio(