CI: Use Cython 3.0

.github/workflows/cbindgen.yml

@@ -55,7 +55,7 @@ jobs:
     - name: Install Cython
       run: |
         python -m pip install --upgrade pip wheel
-        pip install Cython==0.29.*
+        pip install Cython==3.0.2
 
     - name: Build
       run: |