Build: Fix missing NumPy include

Author: andreArtelt

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools"]
+requires = ["setuptools", "numpy"]
 build-backend = "setuptools.build_meta"
 
 [project]

setup.py

@@ -1,3 +1,16 @@
 from setuptools import setup
+from setuptools.command.build_ext import build_ext
 
-setup()
+
+class build_ext_with_numpy(build_ext):
+    def build_extensions(self):
+        import numpy
+
+        numpy_include = numpy.get_include()
+        for ext in self.extensions:
+            ext.include_dirs.append(numpy_include)
+
+        super().build_extensions()
+
+
+setup(cmdclass={"build_ext": build_ext_with_numpy})