fix cluster logic test

Author: dantengsky

tests/sqllogictests/suites/mode/cluster/filter_nulls.test

@@ -155,7 +155,7 @@ Exchange
             ├── scan id: 0
             ├── output columns: [value (#0)]
             ├── read rows: 2000
-            ├── read size: 3.94 KiB
+            ├── read size: 3.95 KiB
             ├── partitions total: 6
             ├── partitions scanned: 3
             ├── pruning stats: [segments: <range pruning: 2 to 1 cost: <slt:ignore>>, blocks: <range pruning: 3 to 3 cost: <slt:ignore>>]