Update cibuildwheel to latest version in CI

Author: takluyver

.github/workflows/tests.yml

@@ -54,14 +54,13 @@ jobs:
   build_wheels:
     name: Build wheels
     runs-on: ubuntu-latest
-    if: github.event_name == 'release' && github.event.action == 'published'
 
     steps:
       - name: Checkout
         uses: actions/checkout@v4
 
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.19.2
+        uses: pypa/cibuildwheel@v4.1.1
         env:
           CIBW_BUILD: cp31[0123]-*
           CIBW_SKIP: "*-musllinux_*  pp*"