ci: Trigger PyPI publish on tag push instead of workflow_run

workflow_run runs the default-branch workflow against the default
branch, so a release-branch point release publishes the wrong source.

Signed-off-by: Siddharth Chandrasekaran <sidcha.dev@gmail.com>

Author: sidcha

.github/workflows/publish-pypi.yml

@@ -8,9 +8,10 @@ name: Publish PyPI
 
 on:
   workflow_dispatch:
-  workflow_run:
-    workflows: ["Create Release"]
-    types: [completed]
+  push:
+    # Sequence of patterns matched against refs/tags
+    tags:
+      - 'v*' # Push events to matching v*, i.e. v1.0, v20.15.10
 
 jobs:
   build_wheels: