ci: run the tests and build the package on every push and pull request

The same job as napalm-fritzbox and napalm-opnsense: Python 3.10, 3.11 and
3.12, pytest, then wheel and sdist. napalm-device-types comes from
git.netork.io first, because PyPI has an unrelated package of that name.

This is the package the other drivers install from git first; here it
installs itself.

.github/workflows/ci.yml

@@ -0,0 +1,45 @@
+name: CI
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+    branches: ["**"]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ["3.10", "3.11", "3.12"]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+          cache: pip
+
+      - name: Install package with dev extras
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install -e ".[dev]"
+
+      - name: Run unit tests
+        run: |
+          python -m pytest -q --tb=short
+
+      - name: Build wheel and sdist
+        run: |
+          python -m pip install build
+          python -m build
+
+      - name: Upload dist artifacts
+        # v4 refuses to run on Gitea ("not currently supported on GHES").
+        uses: actions/upload-artifact@v3
+        with:
+          name: dist-${{ matrix.python-version }}
+          path: dist/*