.list.to_struct() PanicException when used on non-list column

[cmdlineluser]

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

pl.DataFrame({"a": 1}).select(pl.col("a").list.to_struct())
# PanicException: called `Option::unwrap()` on a `None` value

Log output

No response

Issue description

Should raise a SchemaError instead:

pl.DataFrame({"a": 1}).select(pl.col("a").list.first())
# SchemaError: invalid series dtype: expected `List`, got `i64`

Expected behavior

SchemaError

Installed versions

--------Version info---------
Polars:               1.2.1
Index type:           UInt32
Platform:             macOS-13.6.1-arm64-arm-64bit
Python:               3.12.2 (main, Feb  6 2024, 20:19:44) [Clang 15.0.0 (clang-1500.1.0.2.5)]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          <not installed>
connectorx:           <not installed>
deltalake:            <not installed>
fastexcel:            <not installed>
fsspec:               <not installed>
gevent:               <not installed>
great_tables:         <not installed>
hvplot:               <not installed>
matplotlib:           <not installed>
nest_asyncio:         <not installed>
numpy:                1.26.4
openpyxl:             <not installed>
pandas:               2.2.1
pyarrow:              15.0.2
pydantic:             <not installed>
pyiceberg:            <not installed>
sqlalchemy:           <not installed>
torch:                <not installed>
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>