dtype is upcasted silently in list.concat

[gab23r]

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(dict(l = [[0,1,2,]]), schema={'l': pl.List(pl.UInt32)})
df.schema 
# OrderedDict([('l', List(UInt32))])

df.with_columns(pl.col('l').list.concat([3])).schema 
# OrderedDict([('l', List(Int64))])

Log output

No response

Issue description

Don't know if it is expected or it should be tag as feature request. But upcasting silently from AnyValue did not seem right to me in that case.

Expected behavior

Schema is unchanged or raise if the new value do not match the left data type

Installed versions

--------Version info---------
Polars:               0.20.15
Index type:           UInt32
Platform:             macOS-14.1.1-x86_64-i386-64bit
Python:               3.11.6 (v3.11.6:8b6ee5ba3b, Oct  2 2023, 11:18:21) [Clang 13.0.0 (clang-1300.0.29.30)]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          2.2.1
connectorx:           <not installed>
deltalake:            <not installed>
fastexcel:            <not installed>
fsspec:               <not installed>
gevent:               <not installed>
hvplot:               <not installed>
matplotlib:           <not installed>
numpy:                1.26.2
openpyxl:             <not installed>
pandas:               2.1.4
pyarrow:              <not installed>
pydantic:             1.10.13
pyiceberg:            <not installed>
pyxlsb:               <not installed>
sqlalchemy:           2.0.25
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>```

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