Unexpected results comparing booleans to strings

[etrotta]

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

>>> pl.select(pl.lit(True) == '1')
shape: (1, 1)
┌─────────┐
│ literal │
│ ---     │
│ bool    │
╞═════════╡
│ true    │
└─────────┘

>>> pl.select(pl.lit(True) == '2')
shape: (1, 1)
┌─────────┐
│ literal │
│ ---     │
│ bool    │
╞═════════╡
│ false   │
└─────────┘

>>> pl.select(pl.lit(True) == 'foo')
shape: (1, 1)
┌─────────┐
│ literal │
│ ---     │
│ bool    │
╞═════════╡
│ false   │
└─────────┘

Log output

No response

Issue description

According to users in the Discord, "we are too eager to upcast things".

Expected behavior

Expected for it to give an error, the same way it would for integers x strings

>>> pl.select(pl.lit(1) == '1')
Traceback (most recent call last):
    [....]
polars.exceptions.ComputeError: cannot compare string with numeric type (i32)

Installed versions

--------Version info---------
Polars:               0.20.25
Index type:           UInt32
Platform:             Windows-11-10.0.22631-SP0
Python:               3.12.0 (tags/v3.12.0:0fb18b0, Oct  2 2023, 13:03:39) [MSC v.1935 64 bit (AMD64)]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          <not installed>
connectorx:           <not installed>
deltalake:            <not installed>
fastexcel:            0.9.0
fsspec:               <not installed>
gevent:               <not installed>
hvplot:               <not installed>
matplotlib:           3.8.2
nest_asyncio:         <not installed>
numpy:                1.26.1
openpyxl:             3.1.2
pandas:               2.1.2
pyarrow:              15.0.0
pydantic:             2.5.2
pyiceberg:            <not installed>
pyxlsb:               <not installed>
sqlalchemy:           2.0.29
torch:                <not installed>
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>