Bump pypa/cibuildwheel from 2.20 to 2.21

Bumps [pypa/cibuildwheel](https://github.com/pypa/cibuildwheel) from 2.20 to 2.21.
- [Release notes](https://github.com/pypa/cibuildwheel/releases)
- [Changelog](https://github.com/pypa/cibuildwheel/blob/main/docs/changelog.md)
- [Commits](pypa/cibuildwheel@v2.20...v2.21)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/build_cuda.yml

@@ -33,7 +33,7 @@ jobs:
         choco install windows-sdk-8.1
 
     - name: Build wheels
-      uses: pypa/cibuildwheel@v2.20
+      uses: pypa/cibuildwheel@v2.21
       with:
         package-dir: backend/cuda
         output-dir: wheelhouse

.github/workflows/build_default.yml

@@ -63,7 +63,7 @@ jobs:
         platforms: arm64
 
     - name: Build wheels
-      uses: pypa/cibuildwheel@v2.20
+      uses: pypa/cibuildwheel@v2.21
       with:
         output-dir: wheelhouse
       env:

.github/workflows/build_mkl.yml

@@ -25,7 +25,7 @@ jobs:
     - uses: actions/checkout@master
 
     - name: Build wheels
-      uses: pypa/cibuildwheel@v2.20
+      uses: pypa/cibuildwheel@v2.21
       with:
         package-dir: backend/mkl
         output-dir: wheelhouse