Update main.yml

- added python version 3.7 checkout
- removed the explicit protobuf update

.github/workflows/main.yml

@@ -10,6 +10,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
+      - uses: actions/setup-python@v3
+        with:
+          python-version: '3.7' # Version range or exact version of a Python version to use, using SemVer
 
       - name: Install dependencies
         run: pip install -r requirements.txt
@@ -21,9 +24,9 @@ jobs:
       - name: Install streamlit dependencies
         run: |
           pip install -r streamlit_app/requirements.txt
-          pip install --upgrade protobuf
 
       - name: Run streamlit app
         run: |
           nohup streamlit run streamlit_app/app.py &
+          sleep 5
           curl http://localhost:8501