ci: add basic CI

Taken (again) from https://github.com/astral-sh/trusted-publishing-examples

.github/workflows/ci.yml

@@ -0,0 +1,51 @@
+name: Test
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version-file: ".python-version"
+
+      - name: Ruff lint
+        run: uv run ruff check .
+
+      - name: Ruff format
+        run: uv run ruff format --diff .
+
+  test:
+    name: Run tests
+    strategy:
+      matrix:
+        python: [3.9, 3.10, 3.11, 3.12, 3.13]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "{{ matrix.python }}"
+
+      - name: Install dev dependencies
+        run: uv sync --dev
+
+      - name: Run pytest
+        run: uv run pytest