Minor cleanup to CI

Norming a few details, like python specification and venv usage.

.github/workflows/build-and-push.yml

@@ -23,8 +23,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - name: Install dependencies  
-        run: pip install -r requirements-dev.txt
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+      - name: Create and activate virtual environment
+        run: |
+          python -m venv venv
+          source venv/bin/activate
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements-dev.txt
       - name: Run pylint
         run: |
           pylint --recursive y tests/**/*.py
@@ -35,8 +45,18 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+      - name: Create and activate virtual environment
+        run: |
+          python -m venv venv
+          source venv/bin/activate
       - name: Install dependencies
-        run: pip install -r requirements-dev.txt
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements-dev.txt
       - name: Run unit tests
         run: pytest tests/unit