ci: Drop no longer necessary `-Wno-error=array-bounds` #32308

The build log of the "Linux->Windows cross" CI job no longer shows any -Warray-bounds compiler warnings. Therefore, there's no need to suppress them with -Wno-error=array-bounds.

I likely overlooked this when reviewing #29881, as I can run that CI job locally without such warnings even at commit 785649f3977517a4ba45c5d2fedfbda778fb52cb.

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Code Coverage & Benchmarks

For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/32308.

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #30595 (kernel: Introduce initial C header API by TheCharlatan)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

ACK e34f12bdd417862874fe75f5c4c2126a35724de6