add pypi workflow for pushing tags

Author: kleinhenz

.github/workflows/tag.yml

@@ -0,0 +1,28 @@
+name: tag
+on:
+  push:
+    tags:
+      - 'v[0-9]+.[0-9]+.[0-9]+'
+
+jobs:
+  pypi:
+    environment:
+      name: "test.pypi.org"
+      url: "https://test.pypi.org/project/lbster"
+    needs:
+      - "build"
+    permissions:
+      id-token: "write"
+    runs-on: "ubuntu-latest"
+    steps:
+      - uses: "actions/download-artifact@v4"
+        with:
+          name: "python-package-distributions"
+          path: "dist/"
+      - uses: "pypa/gh-action-pypi-publish@release/v1"
+        with:
+          user: __token__
+          password: ${{ secrets.TEST_PYPI_API_TOKEN }}
+          repository-url: "https://test.pypi.org/legacy/"
+          skip-existing: true
+          verbose: true