Strict cast of Duration/Datetime to higher precision may overflow

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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

s = pl.Series([2**63 - 1], dtype=pl.Duration)
r = s.cast(pl.Duration("ns"))
print(r)

Log output

shape: (1,)
Series: '' [duration[ns]]
[
        -1µs
]

Issue description

Strict casting should protect against overflows, but it doesn't in this case.

The issue is that this cast multiplies the underlying physical value by 1000. Since our arithmetic currently does not do overflow checks, we have no way to enforce a strict cast here.

Expected behavior

An error (ComputeError?).

Non-strict cast should result in null.

Installed versions

main