Fix dependency download step

Author: dwoz

.github/workflows/build-native-action.yml

@@ -24,6 +24,9 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
+      - name: Install Relenv
+        run: |
+          python3 -m pip install -e .
       - name: Download Dependencies
         run: |
           python3 -m relenv build --download-only