Update build_ubuntu.yml

.github/workflows/build_ubuntu.yml

@@ -31,6 +31,7 @@ jobs:
         python -m pip install --upgrade pip
         pip install ruff pytest mypy
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install -e .
         
     - name: Lint with ruff
       run: |