chore(ci): use on create with tags (mongodb-js#2481)

Author: gagik

.github/workflows/merge-release-tag.yml

@@ -1,16 +1,15 @@
 name: Merge Release Tag
 
 on:
-  push:
-    tags:
-      - 'mongosh@[0-9]+.[0-9]+.[0-9]+*'
+  create:
   workflow_dispatch:
 
 permissions:
   contents: none # We use the github app to checkout and push changes
 
 jobs:
   merge-release-tag:
+    if: ${{ github.ref =~ '^refs/tags/mongosh@[0-9]+\.[0-9]+\.[0-9]+(-rc\.[0-9]+)?$' }}
     runs-on: ubuntu-latest
 
     steps: