Fix test publish workflow to trigger on release

Author: shishir-shah-dev

.github/workflows/testpublish.yml

@@ -1,10 +1,8 @@
 name: Publish to TestPyPI
 
 on:
-  #workflow_dispatch:   # allows the workflow to be triggered manually
-  push:
-    branches:
-      - pydi/publish-package
+  release:
+    types: [published]
 
 permissions:
   contents: read