`str.to_datetime` ignores `'%z'`

[MarcoGorelli]

Describe the bug

The code below outputs

╭───────────────────────────────╮
│ a                             │
│ ---                           │
│ Timestamp(Microseconds, None) │
╞═══════════════════════════════╡
│ 2020-01-01 00:00:00           │
╰───────────────────────────────╯

thus ignoring the '%z'

To Reproduce

import daft
df = daft.from_pydict({'a': ['2020-01-01T00:00:00+01:00']})
df.select(daft.col('a').str.to_datetime('%Y-%m-%dT%H:%M:%S%z')).collect()

Expected behavior

probably

shape: (1, 1)
┌─────────────────────────┐
│ a                       │
│ ---                     │
│ datetime[μs, UTC]       │
╞═════════════════════════╡
│ 2019-12-31 23:00:00 UTC │
└─────────────────────────┘

Component(s)

Native Runner

Additional context

spotted in narwhals