Install gcc 12 in the github workflow for the test

Author: loonycyborg

.github/workflows/runtest.yml

@@ -40,6 +40,9 @@ jobs:
           python -m pip install --upgrade pip setuptools wheel
           python -m pip install -r requirements-dev.txt
           # sudo apt-get update
+          sudo apt-get install gcc-12 g++-12
+          sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 100
+          sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 100
 
       - name: runtest ${{ matrix.os }}
         run: |