Small fix to github code check workflow

.github/workflows/code_checks.yml

@@ -43,6 +43,7 @@ jobs:
           cache-dependency-path: 'frontend/package-lock.json'
       - name: Install dependencies and check code
         run: |
+          cd backend
           poetry env use '3.10'
           source .venv/bin/activate
           poetry install --with test --all-extras