Revert "CI install ninja from pypi"

Author: MatthewSZhang

.github/workflows/ci.yml

@@ -74,7 +74,9 @@ jobs:
           CIBW_ARCHS_LINUX: auto64
           CIBW_ARCHS_MACOS: x86_64 arm64
           CIBW_ARCHS_WINDOWS: auto64
-          CIBW_BEFORE_ALL_LINUX: yum install -y python3-devel
+          CIBW_BEFORE_ALL_LINUX: yum install -y ninja-build python3-devel
+          CIBW_BEFORE_ALL_WINDOWS: choco install ninja
+          CIBW_BEFORE_ALL_MACOS: brew install ninja
     - name: Upload package
       uses: actions/upload-artifact@v4
       with:

pixi.lock

@@ -34,7 +34,7 @@ type = ["mypy"]
 doc = ["furo"]
 
 [build-system]
-requires = ["meson-python", "cython", "scikit-learn", "build", "ninja"]
+requires = ["meson-python", "cython", "scikit-learn", "build"]
 build-backend = "mesonpy"
 
 [tool.pixi.project]