Unable to cast u8 to enum

[neeldugar]

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


df = pl.DataFrame({
    "a": [0, 1, 2, 3, 4]
}, schema={"a": pl.UInt8})

dtype = pl.Enum(["et1", "et2", "et3", "et4", "et5"])
df = df.select([
    pl.col("a").cast(dtype),
])
print(df)

Log output

thread '' panicked at /Users/runner/work/polars/polars/crates/polars-arrow/src/array/binview/mod.rs:256:9:
assertion failed: i < self.len()
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
...
pyo3_runtime.PanicException: assertion failed: i < self.len()

Issue description

Probably follows from #13409 and #13955 respectively

Expected behavior

No Rust exception to get thrown & valid cast to occur if elements all fall within enum range.

Installed versions

--------Version info---------
Polars:               0.20.21
Index type:           UInt32
Platform:             macOS-13.6.5-arm64-arm-64bit
Python:               3.12.3 (main, Apr  9 2024, 08:09:14) [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>
hvplot:               0.9.2
matplotlib:           <not installed>
nest_asyncio:         <not installed>
numpy:                1.26.4
openpyxl:             <not installed>
pandas:               2.2.2
pyarrow:              15.0.2
pydantic:             <not installed>
pyiceberg:            <not installed>
pyxlsb:               <not installed>
sqlalchemy:           <not installed>
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>

[reswqa]

Thanks! This should be completely covered by #15738, I will close this and in favor of that one.