Remove Cython 3 restriction

pyproject.toml

@@ -1,7 +1,7 @@
 [build-system]
 requires = [
     "setuptools",
-    "cython>=0.25,<3.0",
+    "cython>=0.25",
     "cymem>=2.0.2,<2.1.0",
     "preshed>=3.0.2,<3.1.0",
     "murmurhash>=0.28.0,<1.1.0",

requirements.txt

@@ -24,7 +24,7 @@ setuptools
 packaging>=20.0
 # Development dependencies
 pre-commit>=2.13.0
-cython>=0.25,<3.0
+cython>=0.25
 pytest>=5.2.0,!=7.1.0
 pytest-timeout>=1.3.0,<2.0.0
 mock>=2.0.0,<3.0.0