fix: fix pyarrow len aggregation behaviour for depth-1 exprs
#3239
| Job | Run time |
|---|---|
| 2m 6s | |
| 1m 44s | |
| 2m 8s | |
| 1m 48s | |
| 1m 50s | |
| 3m 45s | |
| 47s | |
| 14m 8s |
len aggregation behaviour for depth-1 exprs
#3239
| Job | Run time |
|---|---|
| 2m 6s | |
| 1m 44s | |
| 2m 8s | |
| 1m 48s | |
| 1m 50s | |
| 3m 45s | |
| 47s | |
| 14m 8s |