test: Add tests for before and limit parameters for list SqliteSaver (#5816)

**Description:** 

Add test for before and limit parameters for the list in SqliteSaver
which was marked as TODO.

---------

Co-authored-by: Caspar Broekhuizen <caspar@langchain.dev>

libs/checkpoint-sqlite/tests/test_sqlite.py

@@ -116,7 +116,17 @@ class TestSqliteSaver:
                 search_results_5[1].config["configurable"]["checkpoint_ns"],
             } == {"", "inner"}
 
-            # TODO: test before and limit params
+            # search with before param
+            search_results_6 = list(saver.list(None, before=search_results_5[1].config))
+            assert len(search_results_6) == 1
+            assert search_results_6[0].config["configurable"]["thread_id"] == "thread-1"
+
+            # search with limit param
+            search_results_7 = list(
+                saver.list({"configurable": {"thread_id": "thread-2"}}, limit=1)
+            )
+            assert len(search_results_7) == 1
+            assert search_results_7[0].config["configurable"]["thread_id"] == "thread-2"
 
     def test_search_where(self) -> None:
         # call method / assertions