more working around hardcoded pip install Cython calls

.github/workflows/bootstrap.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v2
         with:
-             python-version: '3.x'        
+             python-version: '3.10'        
       - name: Check out
         uses: actions/checkout@v2
       - name: Install prerequisites

bootstrap.sh

@@ -54,7 +54,6 @@ ln -s g6k-env/bin/activate ./
 source ./activate
 
 $PIP install -U pip
-$PIP install Cython
 $PIP install cysignals
 
 
@@ -106,7 +105,6 @@ cd ..
 
 git clone https://github.com/fplll/fpylll g6k-fpylll
 cd g6k-fpylll || exit
-$PIP install Cython
 $PIP install -r requirements.txt
 $PIP install -r suggestions.txt
 $PYTHON setup.py clean