InvalidOperationError when using fill_null after .list.sum() on bool list

[0xbe7a]

Checks

• I have checked that this issue has not already been reported.
• I have confirmed this bug exists on the latest version of Polars.

Reproducible example

import polars as pl

df = pl.DataFrame({"x": [[True, True, False]]})


df.select(
    pl.col("x")
    .list.sum()
    .fill_null(0)
)

Log output

Traceback (most recent call last):
  File "/Users/belastoyan/Documents/[redacted]/test.py", line 8, in <module>
    df.select(
  File "/Users/belastoyan/Documents/[redacted]]/.pixi/envs/default/lib/python3.12/site-packages/polars/dataframe/frame.py", line 8137, in select
    return self.lazy().select(*exprs, **named_exprs).collect(_eager=True)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/belastoyan/Documents/[redacted]/.pixi/envs/default/lib/python3.12/site-packages/polars/lazyframe/frame.py", line 1816, in collect
    return wrap_df(ldf.collect(callback))
                   ^^^^^^^^^^^^^^^^^^^^^
polars.exceptions.InvalidOperationError: could not determine supertype of: [bool, dyn int]

Issue description

This used to work on polars 0.20.25, now it's throwing an error. I believe it's a valid expression.

Expected behavior

Should output 2

Installed versions

--------Version info---------
Polars: 0.20.26
Index type: UInt32
Platform: macOS-14.4-arm64-arm-64bit
Python: 3.12.3 | packaged by conda-forge | (main, Apr 15 2024, 18:35:20) [Clang 16.0.6 ]

----Optional dependencies----
adbc_driver_manager:
cloudpickle:
connectorx:
deltalake:
fastexcel:
fsspec:
gevent:
hvplot:
matplotlib:
nest_asyncio: 1.6.0
numpy: 1.26.4
openpyxl:
pandas: 2.2.2
pyarrow: 16.0.0
pydantic:
pyiceberg:
pyxlsb:
sqlalchemy:
torch:
xlsx2csv:
xlsxwriter: