test: add tox workflow

.github/workflows/tox.yml

@@ -0,0 +1,35 @@
+name: Run Tox
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [ '3.8', '3.9', '3.10', '3.11' ]
+      fail-fast: false
+    steps:
+      - name: Check out
+        uses: actions/checkout@v4
+
+      - name: Set up python
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
+
+      - name: Load cached venv
+        uses: actions/cache@v4
+        with:
+          path: .tox
+          key: venv-${{ runner.os }}-${{ matrix.python-version }}-${{ hashFiles('poetry.lock') }}
+
+      - name: Install tox
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install tox tox-gh-actions
+      - name: Test with tox
+        run: tox