Rename publish workflow and run only on tags.

This should tidy up the "checks" tab in merge requests.

Author: rwb27

.github/workflows/publish.yml

@@ -1,10 +1,11 @@
-name: Publish to TestPyPI
+name: Publish to PyPI
 
-on: push
-
-#on:
-#    release:
-#      types: [published]
+on:
+  push:
+    # Only try to publish if it's tagged
+    tags:
+      - v**
+      - testpypi-v**
 
 jobs:
     build: