Fix Cython 3 and Numpy 2 compatibility

.github/workflows/ci.yaml

@@ -47,7 +47,7 @@ jobs:
         shell: bash -l {0}
         run: |
           python -m pip install \
-          -f https://7933911d6844c6c53a7d-47bd50c35cd79bd838daf386af554a83.ssl.cf2.rackcdn.com \
+          --index-url https://pypi.anaconda.org/scientific-python-nightly-wheels/simple/ \
           --no-deps --pre --upgrade \
           matplotlib \
           numpy \

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools", "wheel", "numpy", "Cython", "versioneer-518"]
+requires = ["setuptools", "wheel", "numpy", "Cython>=3", "versioneer-518"]
 build-backend = "setuptools.build_meta"
 
 [tool.ruff]

pyresample/ewa/_fornav.pyx

@@ -33,6 +33,7 @@ cimport cpython
 cimport cython
 cimport numpy
 
+numpy.import_array()
 
 cdef extern from "_fornav_templates.h":
     ctypedef float weight_type

pyresample/ewa/_ll2cr.pyx

@@ -28,6 +28,8 @@ from pyproj import Proj
 cimport cython
 cimport numpy
 
+numpy.import_array()
+
 # column and rows can only be doubles for now until the PROJ.4 is linked directly so float->double casting can be done
 # inside the loop
 ctypedef fused cr_dtype:

pyresample/gradient/_gradient_search.pyx

@@ -30,6 +30,7 @@ ctypedef np.double_t DTYPE_t
 cimport cython
 from libc.math cimport fabs, isinf
 
+np.import_array()
 
 @cython.boundscheck(False)
 @cython.wraparound(False)