PanicException broadcasting struct of datetime

[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
from datetime import datetime

s_struct = pl.Series([{'c': datetime(1970, 1, 1, 0, 0)}])
schema = pl.DataFrame().with_columns(a = pl.Series(range(10)), b = s_struct).schema
# pyo3_runtime.PanicException: called `Result::unwrap()` on an `Err` value: SchemaMismatch(ErrString("unexpected value while building Series of type Datetime(Microseconds, None); found value of type Datetime(Microseconds, None): 1970-01-01 00:00:00"))

Log output

thread '<unnamed>' panicked at crates/polars-core/src/scalar/mod.rs:46:92:
called `Result::unwrap()` on an `Err` value: SchemaMismatch(ErrString("unexpected value while building Series of type Datetime(Microseconds, None); found value of type Datetime(Microseconds, None): 1970-01-01 00:00:00"))
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/robin_ga/dev/patito/.venv/lib/python3.10/site-packages/polars/dataframe/frame.py", line 914, in schema
    return Schema(zip(self.columns, self.dtypes))
  File "/Users/robin_ga/dev/patito/.venv/lib/python3.10/site-packages/polars/dataframe/frame.py", line 883, in dtypes
    return self._df.dtypes()
pyo3_runtime.PanicException: called `Result::unwrap()` on an `Err` value: SchemaMismatch(ErrString("unexpected value while building Series of type Datetime(Microseconds, None); found value of type Datetime(Microseconds, None): 1970-01-01 00:00:00"))

Issue description

Bug coming from the patito test suite

Expected behavior

The struct series get broadcasted with no error

Installed versions

--------Version info---------
Polars:              1.9.0
Index type:          UInt32
Platform:            macOS-14.1.1-x86_64-i386-64bit
Python:              3.10.11 (v3.10.11:7d4cc5aa85, Apr  4 2023, 19:05:19) [Clang 13.0.0 (clang-1300.0.29.30)]

----Optional dependencies----
adbc_driver_manager  <not installed>
altair               <not installed>
cloudpickle          <not installed>
connectorx           <not installed>
deltalake            <not installed>
fastexcel            <not installed>
fsspec               <not installed>
gevent               <not installed>
great_tables         <not installed>
matplotlib           <not installed>
nest_asyncio         1.6.0
numpy                2.0.2
openpyxl             <not installed>
pandas               2.2.3
pyarrow              17.0.0
pydantic             2.9.2
pyiceberg            <not installed>
sqlalchemy           <not installed>
torch                <not installed>
xlsx2csv             <not installed>
xlsxwriter           <not installed>```

</details>

[cmdlineluser]

This does run on main, I believe it has already been fixed.

>>> schema
# Schema([('a', Int64),
#       ('b', Struct({'c': Datetime(time_unit='us', time_zone=None)}))])

• Panic during broadcasting struct series containing datetime type #19277