Fixed sql_retriever.py bug

strip gets rid of all the characters you mention in the parameter.

So my sql queries were being truncated if they had an s, a q or an l at the end. Example:

select * from candidates

ended up as 

select * from candidate

llama-index-core/llama_index/core/indices/struct_store/sql_retriever.py

@@ -143,7 +143,7 @@ def parse_response_to_sql(self, response: str, query_bundle: QueryBundle) -> str
         sql_result_start = response.find("SQLResult:")
         if sql_result_start != -1:
             response = response[:sql_result_start]
-        return response.strip().strip("```sql").strip("```").strip()
+        return response.replace("```sql", "").replace("```", "").strip()
 
 
 class PGVectorSQLParser(BaseSQLParser):