Inconsistent error type when doing arithmetics on a non-numeric series

[abalkin]

Polars version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of Polars.

Issue description

The type of the error raised when adding a number to a non-numeric series depends on the dtype of the series:

Reproducible example

>>> from datetime import date
>>> import polars as pl
>>> pl.Series("x", [date.today()]) + 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/a/Work/abalkin/polars/py-polars/polars/internals/series/series.py", line 534, in __add__
    return self._arithmetic(other, "add", "add_<>")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/a/Work/abalkin/polars/py-polars/polars/internals/series/series.py", line 512, in _arithmetic
    other = maybe_cast(other, self.dtype, self.time_unit)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/a/Work/abalkin/polars/py-polars/polars/datatypes.py", line 802, in maybe_cast
    el = py_type(el)  # type: ignore[call-arg]
         ^^^^^^^^^^^
TypeError: function missing required argument 'month' (pos 2)
>>> pl.Series("x", [""]) + 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/a/Work/abalkin/polars/py-polars/polars/internals/series/series.py", line 534, in __add__
    return self._arithmetic(other, "add", "add_<>")
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/a/Work/abalkin/polars/py-polars/polars/internals/series/series.py", line 515, in _arithmetic
    raise ValueError(
ValueError: cannot do arithmetic with series of dtype: Utf8 and argument of type: <class 'str'>

Expected behavior

Expect the same error type in both cases. Probably ValueError error is correct because from Python perspective, dtype is part of the value, not type.

Installed versions

>>> pl.show_versions()
---Version info---
Polars: 0.16.1
Index type: UInt32
Platform: macOS-12.6.3-x86_64-i386-64bit
Python: 3.11.1 (main, Dec 23 2022, 09:40:27) [Clang 14.0.0 (clang-1400.0.29.202)]
---Optional dependencies---
pyarrow: 11.0.0
pandas: 1.5.3
numpy: 1.24.1
fsspec: <not installed>
connectorx: <not installed>
xlsx2csv: 0.8.1
deltalake: <version not detected>
matplotlib: <not installed>

[zundertj]

Changed this to ValueError in #6677. The message will not be exactly the same as the other example you give, given that this is a different code path.