Fix site rebuild on release

The paths filter was applied to tag events, preventing site rebuilds
when releases don't include site changes. Switch to release event
trigger which always fires on new releases, ensuring the site fetches
the latest version from GitHub API.

Closes #1992

.github/workflows/ci-site.yml

@@ -1,10 +1,11 @@
 name: site
 
 on:
+  release:
+    types: [published]
   push:
     branches:
       - master
-    tags:
     paths:
       - ".github/workflows/ci-site.yml"
       - "site/**"
@@ -133,7 +134,7 @@ jobs:
     name: Deploy site
     runs-on: ubuntu-latest
     needs: merge
-    if: github.ref == 'refs/heads/master'
+    if: github.ref == 'refs/heads/master' || github.event_name == 'release'
 
     steps:
       - name: trigger deployment