Expr.hist / Series.hist call fails on empty Series

[codesorcery]

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.Series("a", [None, None, None], dtype=pl.Float32).hist()

Log output

thread '<unnamed>' panicked at crates/polars-ops/src/chunked_array/hist.rs:71:37:
called `Option::unwrap()` on a `None` value

Issue description

Calling Expr.hist / Series.hist on an empty series fails with an error in the corresponding Rust code.
The problematic part in the Rust code is that ChunkAgg::min(ca) and ChunkAgg::max(ca) return None, which is then unwrapped without proper None check handling.

Expected behavior

Return an empty table with the same schema as when Expr.hist / Series.hist is called on non-empty series.

Installed versions

--------Version info---------
Polars:               0.20.6
Index type:           UInt32
Platform:             Linux-5.15.142-flatcar-x86_64-with-glibc2.36
Python:               3.11.6 | packaged by conda-forge | (main, Oct  3 2023, 10:40:35) [GCC 12.3.0]

----Optional dependencies----
adbc_driver_manager:  <not installed>
cloudpickle:          2.2.1
connectorx:           <not installed>
deltalake:            0.15.1
fsspec:               2023.9.2
gevent:               <not installed>
hvplot:               <not installed>
matplotlib:           3.7.3
numpy:                1.24.4
openpyxl:             <not installed>
pandas:               2.0.3
pyarrow:              13.0.0
pydantic:             2.4.2
pyiceberg:            <not installed>
pyxlsb:               <not installed>
sqlalchemy:           2.0.23
xlsx2csv:             <not installed>
xlsxwriter:           <not installed>

[codesorcery]

Thanks, @lukemanley and @ritchie46 !