Update cibuildwheel to 2.3.1

Because cibuildwheel switched to pip 21.3 that uses in-tree builds, we
need to add an explicit clean step. This is because the FreeType built
for 64-bit and 32-bit Windows are not compatible, but as they appear to
be named the same, aren't rebuilt for each wheel, causing linker issues
when mixed.

I'm not sure it's necessary on other platforms as well, but it can't
hurt.

Author: QuLogic

.github/workflows/cibuildwheel.yml

@@ -53,40 +53,52 @@ jobs:
           fetch-depth: 0
 
       - name: Build wheels for CPython 3.10
-        uses: pypa/cibuildwheel@v2.1.1
+        uses: pypa/cibuildwheel@v2.3.1
         env:
           CIBW_BUILD: "cp310-*"
+          CIBW_SKIP: "*-musllinux*"
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux2014
           CIBW_MANYLINUX_I686_IMAGE: manylinux2014
-          CIBW_BEFORE_BUILD: pip install certifi oldest-supported-numpy
+          CIBW_BEFORE_BUILD: >-
+            pip install certifi oldest-supported-numpy &&
+            git clean -fxd build
           MPL_DISABLE_FH4: "yes"
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
       - name: Build wheels for CPython 3.9
-        uses: pypa/cibuildwheel@v2.1.1
+        uses: pypa/cibuildwheel@v2.3.1
         env:
           CIBW_BUILD: "cp39-*"
+          CIBW_SKIP: "*-musllinux*"
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux1
           CIBW_MANYLINUX_I686_IMAGE: manylinux1
-          CIBW_BEFORE_BUILD: pip install certifi oldest-supported-numpy
+          CIBW_BEFORE_BUILD: >-
+            pip install certifi oldest-supported-numpy &&
+            git clean -fxd build
           MPL_DISABLE_FH4: "yes"
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
       - name: Build wheels for CPython 3.8
-        uses: pypa/cibuildwheel@v2.1.1
+        uses: pypa/cibuildwheel@v2.3.1
         env:
           CIBW_BUILD: "cp38-*"
+          CIBW_SKIP: "*-musllinux*"
           CIBW_MANYLINUX_X86_64_IMAGE: manylinux1
           CIBW_MANYLINUX_I686_IMAGE: manylinux1
-          CIBW_BEFORE_BUILD: pip install certifi numpy==1.19.2
+          CIBW_BEFORE_BUILD: >-
+            pip install certifi numpy==1.19.2 &&
+            git clean -fxd build
           MPL_DISABLE_FH4: "yes"
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
 
       - name: Build wheels for PyPy
-        uses: pypa/cibuildwheel@v2.1.1
+        uses: pypa/cibuildwheel@v2.3.1
         env:
           CIBW_BUILD: "pp38-*"
-          CIBW_BEFORE_BUILD: pip install certifi oldest-supported-numpy
+          CIBW_SKIP: "*-musllinux*"
+          CIBW_BEFORE_BUILD: >-
+            pip install certifi oldest-supported-numpy &&
+            git clean -fxd build
           CIBW_ARCHS: ${{ matrix.cibw_archs }}
           PIP_USE_FEATURE: in-tree-build
         if: false && matrix.cibw_archs != 'aarch64'