ci: Enable wheel builds on Python 3.14

This should only end up on the nightly wheel upload for now.

Also, re-enable testing in places where Pillow wheels were previously
missing, but are now available.

Author: QuLogic

.github/workflows/cibuildwheel.yml

@@ -140,15 +140,27 @@ jobs:
           name: cibw-sdist
           path: dist/
 
+      - name: Build wheels for CPython 3.14
+        uses: pypa/cibuildwheel@5f22145df44122af0f5a201f93cf0207171beca7  # v3.0.0
+        with:
+          package-dir: dist/${{ needs.build_sdist.outputs.SDIST_NAME }}
+        env:
+          CIBW_BUILD: "cp314-* cp314t-*"
+          CIBW_ENABLE: "cpython-freethreading cpython-prerelease"
+          CIBW_ARCHS: ${{ matrix.cibw_archs }}
+          CIBW_MANYLINUX_X86_64_IMAGE: manylinux_2_27
+          CIBW_BEFORE_TEST: |
+            python -m pip install \
+              --index-url https://pypi.anaconda.org/scientific-python-nightly-wheels/simple \
+              --upgrade --only-binary=:all: contourpy numpy pillow
+
       - name: Build wheels for CPython 3.13
         uses: pypa/cibuildwheel@5f22145df44122af0f5a201f93cf0207171beca7  # v3.0.0
         with:
           package-dir: dist/${{ needs.build_sdist.outputs.SDIST_NAME }}
         env:
           CIBW_BUILD: "cp313-* cp313t-*"
           CIBW_ENABLE: cpython-freethreading
-          # No free-threading wheels available for aarch64 on Pillow.
-          CIBW_TEST_SKIP: "cp313t-manylinux_aarch64"
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
       - name: Build wheels for CPython 3.12
@@ -167,7 +179,6 @@ jobs:
           CIBW_BUILD: "cp311-*"
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
-
       - name: Build wheels for PyPy
         uses: pypa/cibuildwheel@5f22145df44122af0f5a201f93cf0207171beca7  # v3.0.0
         with:
@@ -176,8 +187,6 @@ jobs:
           CIBW_BUILD: "pp311-*"
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
           CIBW_ENABLE: pypy
-          # No wheels available for Pillow with pp311 yet.
-          CIBW_TEST_SKIP: "pp311*"
         if: matrix.cibw_archs != 'aarch64' && matrix.os != 'windows-latest'
 
       - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02  # v4.6.2