Build win_arm64 wheels in CI

Add a native windows-11-arm runner to the release workflow's wheels
matrix so win_arm64 wheels are built alongside win_amd64, with identical
feature enablement (cibuildwheel 4.1.0, BUILD_EXTENSION=yes, and the
enable=["pypy"] setting inherited from pyproject.toml). On the ARM64
runner cibuildwheel's default arch is ARM64, so no other configuration
change is required.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 62020684-81fd-4cd7-8458-6333d0ad74f1

Author: 2 people

.github/workflows/release.yml

@@ -39,6 +39,7 @@ jobs:
         os:
           - ubuntu-latest
           - windows-latest
+          - windows-11-arm
           - macOS-latest
     steps:
     - name: Check out repository