Try to fix 'FileNotFoundError'

Author: yunline

.github/workflows/build-debian-multiarch.yml

@@ -81,7 +81,8 @@ jobs:
           apt-get update --fix-missing
           apt-get upgrade -y
           apt-get install libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev libfreetype6-dev libportmidi-dev libjpeg-dev fontconfig -y
-          apt-get install python3-setuptools python3-dev python3-pip python3-wheel python3-sphinx python3-cython -y
+          apt-get install python3-setuptools python3-dev python3-pip python3-wheel python3-sphinx -y
+          pip3 -m pip install cython
 
         # Build a wheel, install it for running unit tests
         run: |