Update .github/workflows/main.yml

Co-authored-by: Miguel Caballer Fernandez <micafer1@upv.es>

Author: tisonkun

.github/workflows/main.yml

@@ -275,7 +275,9 @@ jobs:
             ${{ runner.os }}-pip-
 
       - name: Install Python Dependencies
-        run: pip install -r requirements-ci.txt
+        run: |
+          pip install --upgrade pip
+          pip install -r requirements-ci.txt
 
       - name: Install Library Into Virtualenv
         run: |