fix pysap installation issue

Author: tobias-liaudat

.github/workflows/CD-build.yml

@@ -37,11 +37,14 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install -r develop.txt
           python -m pip install twine
+          python -m pip install PyQt5
           python -m pip install pyqtgraph
           python -m pip install git+https://github.com/CEA-COSMIC/pysap.git@2e26a71024b5a0419b27d4b3fc5cdee77bd3919b
-          python -m pip install -r docs/requirements.txt
           python -m pip install GalSim
-          python -m pip install .
+
+      - name: Install requirements
+        run: |
+          python -m pip install -r docs/requirements.txt
 
       - name: Install MCCD
         run: python -m pip install .