add black to CI

Author: jpstroop

.github/workflows/ci.yml

@@ -95,4 +95,31 @@ jobs:
 
       - name: Check import formatting
         run: |
-          pdm run isort --check --verbose
+          pdm run isort --check --verbose
+
+  black:
+    name: black
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python 3.13
+        uses: actions/setup-python@v4
+        with:
+          python-version: "3.13"
+
+      - name: Install PDM
+        run: |
+          python -m pip install --upgrade pip
+          pip install pdm
+
+      - name: Install dependencies
+        run: |
+          pdm install -G:all
+
+      - name: Check code style
+        run: |
+          pdm run black --check --verbose