partly revert https://github.com/pyproj4/pyproj/commit/14522ad3e33fcaff91993ece796ee70aeaec9b90

Index: pyproject.toml
--- pyproject.toml.orig
+++ pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=61.0.0", "wheel", "cython>=3.1"]
+requires = ["setuptools>=61.0.0", "wheel", "cython>=3"]
 build-backend = "setuptools.build_meta"
 
 [project]
