chore: update latest workflow to only allow pointing at 8.x (ionic-team#8319)

Author: markemer

.github/workflows/publish-npm-latest.yml

@@ -15,7 +15,7 @@ permissions:
 
 jobs:
   deploy-npm-latest:
-    if: github.ref == 'refs/heads/main'
+    if: github.ref == 'refs/heads/8.x'
     runs-on: macos-15
     timeout-minutes: 30
     steps: