Add Actions publishing

Author: tomkins

.github/workflows/publish.yml

@@ -0,0 +1,92 @@
+name: Publish
+
+on:
+  push:
+    tags:
+      - "*"
+
+jobs:
+  build:
+    name: Build packages
+    runs-on: ubuntu-24.04
+    environment: publish
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+      - name: Build packages
+        run: |
+          pip install -r requirements/testing.txt
+          make package
+      - name: Upload packages
+        uses: actions/upload-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+          if-no-files-found: error
+
+  publish-to-pypi:
+    name: Publish package on PyPI
+    needs:
+      - build
+    runs-on: ubuntu-24.04
+    environment:
+      name: pypi
+      url: https://pypi.org/project/${{ github.event.repository.name }}/${{ github.ref_name }}/
+    permissions:
+      id-token: write
+
+    steps:
+      - name: Download packages
+        uses: actions/download-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+      - name: Publish to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+
+  github-release:
+    name: Publish package on GitHub Releases
+    needs:
+      - build
+    runs-on: ubuntu-24.04
+    environment:
+      name: github-releases
+      url: ${{ github.server_url }}/${{ github.repository }}/releases/tag/${{ github.ref_name }}
+    permissions:
+      contents: write
+      id-token: write
+
+    steps:
+      - name: Download packages
+        uses: actions/download-artifact@v4
+        with:
+          name: python-package-distributions
+          path: dist/
+      - name: Sign packages
+        uses: sigstore/[email protected]
+        with:
+          inputs: >-
+            ./dist/*.tar.gz
+            ./dist/*.whl
+      - name: Create GitHub Release
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: >-
+          gh release create
+          "$GITHUB_REF_NAME"
+          --repo "$GITHUB_REPOSITORY"
+          --title "${GITHUB_REPOSITORY#*/} $GITHUB_REF_NAME"
+      - name: Upload artifact signatures to GitHub Release
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: >-
+          gh release upload
+          "$GITHUB_REF_NAME" dist/**
+          --repo "$GITHUB_REPOSITORY"