Use the release environment for TestPyPI publishes (#146)

Trusted publishing is set up to require that the release be done by
`publish.yml` in the `release` environment, which is only set up for the
PyPI environment.

Co-authored-by: Stan Ulbrych <stan@python.org>

Author: pganssle

.github/workflows/publish.yml

@@ -55,6 +55,13 @@ jobs:
     runs-on: ubuntu-latest
     needs: test-package
 
+    environment:
+      name: release
+      url: >-
+        https://test.pypi.org/project/tzdata/${{
+          github.event.release.tag_name
+        }}
+
     permissions:
       id-token: write