Add Windows ARM64 support in CI

[Harishmcw]

This PR introduces official support for Windows ARM64.

Changes:

• Updated soundfile.py to correctly detect ARM64/AArch64 architectures on Windows and load the corresponding libsndfile_arm64.dll.
• Added windows-11-arm to the GitHub Actions matrix and included arm64 architecture across supported OS versions.

[mayankag-qti]

@khmyznikov FYI

[khmyznikov]

@Harishmcw tests are fine?

[Harishmcw]

@Harishmcw tests are fine?

Yes, the tests are fine. The previous failures were due to a regression on newer Windows Server 2025 runners, which this PR addresses. The pipeline is now green across all platforms, and I've verified that the Windows ARM64 tests are also passing correctly: pipeline

[bastibe]

Beautiful, thank you very much!

[Harishmcw]

Thanks for merging the PR.

Could you please let me know when the next release on PyPI is planned?
Looking forward to using the WoA wheels via pip!

[bastibe]

I'll try to get around to it this weekend. Please do message me again should I forget.

[Harishmcw]

I'll try to get around to it this weekend. Please do message me again should I forget.

Hi @bastibe,

Just a gentle ping on this whenever you get a chance. Thanks!