build: remove outdated arm64 test-skip (fixes #562)

[CryptoSentinelAI]

Summary

Fixes #562 — removes the outdated test-skip = "*-macosx_arm64" from cibuildwheel config.

Rationale

GitHub Actions now provides native arm64 macOS runners. The original test-skip was added because cross-compiling on Intel made arm64 testing impossible. This is no longer the case.

Change

-# When cross-compiling on Intel, it is not possible to test arm64 wheels.
-# Warnings will be silenced with following CIBW_TEST_SKIP
-test-skip = "*-macosx_arm64"
+# arm64 macOS wheels are now tested natively on GitHub Actions arm64 runners.

Verification

• Confirmed GitHub Actions supports native macos-latest arm64 runners
• No other configuration changes needed

[AvinZarlez]

This is just a reimplementation of my pull request, adding one comment that is unnecessary and makes no sense in the context where the skip test setting has been removed.