add pytest to CI pipeline (#286)

.github/workflows/pytest.yaml

@@ -0,0 +1,22 @@
+name: pytest
+
+on: [push, pull_request]
+
+jobs:
+  pytest:
+    name: Run tests
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+          pip install -r requirements-dev.txt
+
+      - name: Run tests
+        run: |
+          pytest tagstudio/tests/