Add Github action to verify packaging

.github/workflows/packaging.yml

@@ -0,0 +1,22 @@
+name: Packaging
+
+on: [push, pull_request]
+
+jobs:
+  packaging:
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
+    runs-on: ubuntu-22.04
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v4
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.11'
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install tox
+    - name: Build package
+      run: |
+        tox -e packaging

pyproject.toml

@@ -67,6 +67,9 @@ dev = [
   # Docs.
   "Sphinx==8.1.3 ; python_version>='3.11'",
   "sphinx-rtd-theme==3.0.2 ; python_version>='3.11'",
+  # Packaging.
+  "build==1.2.2 ; python_version>='3.11'",
+  "twine==6.0.1 ; python_version>='3.11'",
 ]
 
 [project.urls]

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = lint, tests, docs
+envlist = lint, tests, docs, packaging
 isolated_build = True
 
 [testenv]
@@ -23,3 +23,9 @@ commands =
 description = Build the HTML documentation.
 commands =
     sphinx-build -a -b html -W --keep-going docs/ docs/build
+
+[testenv:packaging]
+description = Build the Python package.
+commands =
+    pyproject-build .
+    twine check --strict dist/*