Bump pypa/cibuildwheel from 2.20.0 to 2.21.0 (#181)

Bumps [pypa/cibuildwheel](https://github.com/pypa/cibuildwheel) from 2.20.0 to 2.21.0.
- [Release notes](https://github.com/pypa/cibuildwheel/releases)
- [Changelog](https://github.com/pypa/cibuildwheel/blob/main/docs/changelog.md)
- [Commits](pypa/cibuildwheel@v2.20.0...v2.21.0)

---
updated-dependencies:
- dependency-name: pypa/cibuildwheel
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/tests.yml

@@ -61,7 +61,7 @@ jobs:
         with:
           submodules: true
           fetch-depth: 0
-      - uses: pypa/cibuildwheel@v2.20.0
+      - uses: pypa/cibuildwheel@v2.21.0
       - uses: actions/upload-artifact@v4
         with:
           name: binary-${{ matrix.os }}