Use the "release" environment on TestPyPI

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.

Author: pganssle

.github/workflows/publish.yml

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