[Fix] Update for Docker Images

Due to an update of the docker images minor changes are required for the CI

.gitlab-ci.yml

@@ -109,7 +109,8 @@ ubuntu:
   before_script:
     - apt-get -y remove python3-sympy
     - ln -s /usr/include/locale.h /usr/include/xlocale.h
-    - pip3 install `grep -Eo 'sympy[>=]+[0-9\.]+' setup.py | sed 's/>/=/g'`
+    - pip3 install sympy==1.6
+    # - pip3 install `grep -Eo 'sympy[>=]+[0-9\.]+' setup.py | sed 's/>/=/g'`
     # - pip3 install `grep -Eo 'sympy[>=]+[0-9\.]+' setup.py | sed 's/>/=/g'`
   script:
     - export NUM_CORES=$(nproc --all)