Set up automatic publishing to PyPI

Author: mitya57

.github/workflows/main.yml

@@ -38,3 +38,20 @@ jobs:
         run: flake8 --max-line-length=88 .
       - name: Run mypy
         run: mypy --strict --ignore-missing-imports secretstorage/ tests/
+  pypi-publish:
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/SecretStorage
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/checkout@v5
+      - uses: actions/setup-python@v6
+        with:
+          python-version: '3.13'
+      - run: pip install build
+      - run: python -m build
+      - if: success()
+        uses: pypa/gh-action-pypi-publish@release/v1