fix(search.py):remove hard page_size (#8242)

### What problem does this PR solve?

Fix the restriction of forcing similarity_threshold=0 and page_size=30
when doc_ids is not empty

#8228

---------

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

rag/nlp/search.py

@@ -380,15 +380,12 @@ class Dealer:
                 rank_feature=rank_feature)
         # Already paginated in search function
         idx = np.argsort(sim * -1)[(page - 1) * page_size:page * page_size]
-
-
         dim = len(sres.query_vector)
         vector_column = f"q_{dim}_vec"
         zero_vector = [0.0] * dim
+        sim_np = np.array(sim)
         if doc_ids:
             similarity_threshold = 0 
-            page_size = 30
-        sim_np = np.array(sim)
         filtered_count = (sim_np >= similarity_threshold).sum()    
         ranks["total"] = int(filtered_count) # Convert from np.int64 to Python int otherwise JSON serializable error
         for i in idx: