ci: use release event for trusted publishing

Tag-based triggers don't work with npm Trusted Publishing because
npm expects workflow_ref from a branch, not a tag ref.

Author: koistya

.github/workflows/release.yml

@@ -1,8 +1,8 @@
 name: Release
 
 on:
-  push:
-    tags: ["v*"]
+  release:
+    types: [published]
 
 jobs:
   publish: