CI: prepare workflow for trusted publishing

Author: bcbnz

.github/workflows/publish.yml

@@ -0,0 +1,59 @@
+name: Build and publish Python distributions
+
+# Build distributions on every push. Only tagged versions will be published.
+on: push
+
+jobs:
+  build:
+    name: Build distribution
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v6
+      with:
+        persist-credentials: false
+
+    - name: Set up Python
+      uses: actions/setup-python@v6
+      with:
+        python-version: "3.x"
+
+    - name: Install build tools
+      run: python3 -m pip install build --user
+
+    - name: Build source tarball and binary wheel
+      run: python3 -m build
+
+    - name: Store the distribution packages
+      uses: actions/upload-artifact@v5
+      with:
+        name: python-package-distributions
+        path: dist/
+
+  publish-to-pypi:
+    name: Publish to PyPI
+
+    # Only publish for version tags.
+    if: startsWith(github.ref, 'refs/tags/v')
+
+    needs:
+    - build
+
+    runs-on: ubuntu-latest
+
+    environment:
+      name: pypi
+      url: https://pypi.org/p/matplotlib-pgfutils
+
+    permissions:
+      id-token: write
+
+    steps:
+    - name: Download the built distributions
+      uses: actions/download-artifact@v6
+      with:
+        name: python-package-distributions
+        path: dist/
+
+    - name: Publish distributions to PyPI
+      uses: pypa/gh-action-pypi-publish@release/v1