DataFrame construction in row orientation fails on invalid values even with strict = False

[ruomad]

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.DataFrame([{'a': 1.0, 'b': ''}], schema = {'a': pl.Float64, 'b': pl.Float64}, orient = 'row', strict = False)
pl.DataFrame([{'a': 1.0, 'b': 'x'}], schema = {'a': pl.Float64, 'b': pl.Float64}, orient = 'row', strict = False)
pl.DataFrame([[1.0, '']], schema = {'a': pl.Float64, 'b': pl.Float64}, orient = 'row', strict = False)
pl.DataFrame([[1.0, 'x']], schema = {'a': pl.Float64, 'b': pl.Float64}, orient = 'row', strict = False)

both yield :

polars.exceptions.ComputeError: could not append value: "" of type: str to the builder; make sure that all rows have the same schema or consider increasing `infer_schema_length`

or

polars.exceptions.ComputeError: could not append value: "x" of type: str to the builder; make sure that all rows have the same schema or consider increasing `infer_schema_length`

Log output

No response

Issue description

DataFrame construction from rows fails on unconvertible values even if strict = False
@stinodego: it fails even if string is not empty
It works as expected when constructing from columns

Expected behavior

Invalid values converted to null

Installed versions

--------Version info---------
Polars:               0.20.22
Index type:           UInt32
Platform:             Windows-10-10.0.19045-SP0
Python:               3.12.3 (tags/v3.12.3:f6650f9, Apr  9 2024, 14:05:25) [MSC v.1938 64 bit (AMD64)]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          <not installed>
connectorx:           <not installed>
deltalake:            <not installed>
fastexcel:            0.10.4
fsspec:               <not installed>
gevent:               <not installed>
hvplot:               <not installed>
matplotlib:           <not installed>
nest_asyncio:         <not installed>
numpy:                1.26.4
openpyxl:             3.1.2
pandas:               2.2.2
pyarrow:              16.0.0
pydantic:             <not installed>
pyiceberg:            <not installed>
pyxlsb:               <not installed>
sqlalchemy:           <not installed>
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>