Publish a GitHub Release after tagging (#782)

Co-authored-by: Abhinav Singh <126065+abhinavsingh@users.noreply.github.com>

.github/workflows/test-library.yml

@@ -764,4 +764,38 @@ jobs:
         to the just published release back to GitHub
       run: >-
         git push --atomic origin '${{ needs.pre-setup.outputs.git-tag }}'
+
+  publish-github-release:
+    name: >-
+      Publish a GitHub Release for
+      ${{ needs.pre-setup.outputs.git-tag }}
+    needs:
+    - post-release-repo-update
+    - pre-setup  # transitive, for accessing settings
+    runs-on: Ubuntu-latest
+
+    permissions:
+      contents: write
+
+    steps:
+    - name: Download all the dists
+      uses: actions/download-artifact@v2
+      with:
+        name: python-package-distributions
+        path: dist/
+
+    - name: >-
+        Publish a GitHub Release for
+        ${{ needs.pre-setup.outputs.git-tag }}
+      uses: softprops/action-gh-release@v1
+      with:
+        # body/body_path:  # FIXME: Use once Towncrier is integrated.
+        discussion_category_name: Announcements
+        fail_on_unmatched_files: true
+        files: |
+          dist/${{ needs.pre-setup.outputs.sdist-artifact-name }}
+          dist/${{ needs.pre-setup.outputs.wheel-artifact-name }}
+        name: ${{ needs.pre-setup.outputs.git-tag }}
+        tag_name: ${{ needs.pre-setup.outputs.git-tag }}
+        target_commitish: ${{ github.event.inputs.release-commitish }}
 ...