cut: use ? instead of match

[cakebaker]

This PR uses ? instead of match in three places where the None arm returns None.

[xtqqczze]

I guess this is a false negative for clippy::question_mark.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/pr/bounded-memory (fails in this run but passes in the 'main' branch)
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[codspeed-hq]

Merging this PR will improve performance by 5.6%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 2 improved benchmarks
✅ 298 untouched benchmarks
⏩ 46 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	cut_fields_tab	26.8 ms	25.4 ms	+5.46%
⚡	Simulation	cut_fields_custom_delim	30.9 ms	29.3 ms	+5.6%

---

_{Comparing cakebaker:cut_replace_match (edf71d9) with main (c6a57bb)}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[sylvestre]

terrific

[cakebaker]

@xtqqczze thanks for the hint, I opened an issue there: rust-lang/rust-clippy#16751