fix: Response getting ']' brackets, it's inconsistent (#1611)

Co-authored-by: Pavan-Microsoft <v-kupavan@microsoft.com>

code/backend/batch/utilities/parser/output_parser_tool.py

@@ -22,10 +22,13 @@ def _get_source_docs_from_answer(self, answer):
 
     def _make_doc_references_sequential(self, answer):
         doc_matches = list(re.finditer(r"\[doc\d+\]", answer))
+        updated_answer = answer
+        offset = 0
         for i, match in enumerate(doc_matches):
-            start, end = match.span()
-            answer = answer[:start] + f"[doc{i + 1}]" + answer[end:]
-        return answer
+            start, end = match.start() + offset, match.end() + offset
+            updated_answer = updated_answer[:start] + f"[doc{i + 1}]" + updated_answer[end:]
+            offset += len(f"[doc{i + 1}]") - (end - start)
+        return updated_answer
 
     def parse(
         self,