Fix: fix retrieval tesing wrong pagination (#7174)

### What problem does this PR solve?

Fix retrieval testing wrong pagination. #7171 

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

rag/nlp/search.py

@@ -15,6 +15,7 @@
 #
 import logging
 import re
+import math
 from collections import OrderedDict
 from dataclasses import dataclass
 
@@ -353,11 +354,13 @@ class Dealer:
             return ranks
 
         RERANK_LIMIT = 64
-        req = {"kb_ids": kb_ids, "doc_ids": doc_ids, "page": page, "size": RERANK_LIMIT,
+        RERANK_LIMIT = int(RERANK_LIMIT//page_size + ((RERANK_LIMIT%page_size)/(page_size*1.) + 0.5)) * page_size if page_size>1 else 1
+        req = {"kb_ids": kb_ids, "doc_ids": doc_ids, "page": math.ceil(page_size*page/RERANK_LIMIT), "size": RERANK_LIMIT,
                "question": question, "vector": True, "topk": top,
                "similarity": similarity_threshold,
                "available_int": 1}
 
+
         if isinstance(tenant_ids, str):
             tenant_ids = tenant_ids.split(",")
 
@@ -373,6 +376,7 @@ class Dealer:
             sim, tsim, vsim = self.rerank(
                 sres, question, 1 - vector_similarity_weight, vector_similarity_weight,
                 rank_feature=rank_feature)
+        # Already paginated in search function
         idx = np.argsort(sim * -1)[(page - 1) * page_size:page * page_size]