Remove install of Python build prereqs in CIBW_BEFORE_BUILD

Author: mkoeppe

.github/workflows/buildwheel.yml

@@ -38,8 +38,7 @@ jobs:
           CIBW_MANYLINUX_I686_IMAGE: manylinux2014
           CIBW_BEFORE_ALL_MACOS: bin/cibw_before_all_macosx_x86_64.sh
           CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows.sh
-          CIBW_BEFORE_BUILD_WINDOWS: msys2 -c bin/cibw_before_build_windows.sh
-          CIBW_BEFORE_BUILD: pip install numpy setuptools cython delvewheel
+          CIBW_BEFORE_BUILD_WINDOWS: pip install delvewheel && msys2 -c bin/cibw_before_build_windows.sh
 
       - uses: actions/upload-artifact@v4
         with:

bin/cibw.sh

@@ -15,8 +15,7 @@ export CIBW_ARCHS_MACOS="arm64"
 export CIBW_BEFORE_ALL_MACOS=bin/cibw_before_all_macosx_arm64.sh
 export CIBW_BEFORE_ALL_WINDOWS='C:\\msys64\\usr\\bin\\bash bin/cibw_before_all_windows.sh'
 
-export CIBW_BEFORE_BUILD='pip install numpy cython delvewheel'
-export CIBW_BEFORE_BUILD_WINDOWS='C:\\msys64\\usr\\bin\\bash bin/cibw_before_build_windows.sh'
+export CIBW_BEFORE_BUILD_WINDOWS='pip install delvewheel && C:\\msys64\\usr\\bin\\bash bin/cibw_before_build_windows.sh'
 
 export CIBW_TEST_COMMAND="python -m flint.test"  # override setting in pyproject.toml