fix: assertion error on records-shard merge

This issue was difficult to debug. Usually, GROUP BY would also return sorted data because PG sorts data by default when using GROUP By. Except that for small arrays, it doesn't sort. Adding excplicit sort order to make_shard_sql fixes #2

lbsntransform/output/hll/hll_functions.py

@@ -85,6 +85,7 @@ def make_shard_sql(values_str: str) -> str:
             VALUES {values_str}
             ) s(base_id, metric_id, item_value)
             GROUP BY base_id, metric_id
+            ORDER BY base_id, metric_id
             '''
         return insert_sql