Fix no-bigint build failures, check those in CI

[fasterthanlime]

I forgot to fix a couple lines in the last PR — now they're checked by pre-commit, before committing (I'm assuming?) and in CI.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.55%. Comparing base (b09b969) to head (ac903d0). Report is 4 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #138 +/- ## ======================================= Coverage 94.55% 94.55% ======================================= Files 12 12 Lines 2040 2040 ======================================= Hits 1929 1929 Misses 111 111 ``` | [Files with missing lines](https://app.codecov.io/gh/pydantic/jiter/pull/138?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic) | Coverage Δ | | |---|---|---| | [crates/jiter/src/value.rs](https://app.codecov.io/gh/pydantic/jiter/pull/138?src=pr&el=tree&filepath=crates%2Fjiter%2Fsrc%2Fvalue.rs&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic#diff-Y3JhdGVzL2ppdGVyL3NyYy92YWx1ZS5ycw==) | `94.10% <ø> (ø)` | | ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/pydantic/jiter/pull/138?dropdown=coverage&src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/pydantic/jiter/pull/138?dropdown=coverage&src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic). Last update [b09b969...ac903d0](https://app.codecov.io/gh/pydantic/jiter/pull/138?dropdown=coverage&src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=pydantic).

[codspeed-hq[bot]]

CodSpeed Performance Report

Merging #138 will degrade performances by 10.99%

_{Comparing bearcove:bigint-check (ac903d0) with main (b09b969)}

Summary

❌ 1 regressions ✅ 72 untouched benchmarks

:warning: Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	main	bearcove:bigint-check	Change
❌	sentence_jiter_value	7.9 µs	8.9 µs	-10.99%

[fasterthanlime]

CI failure is unrelated and perf regression is.. unexplainable. Oh well.