add script

package.json

@@ -38,6 +38,7 @@
     "slackbot-proxy:build": "turbo run build --filter @growi/slackbot-proxy",
     "slackbot-proxy:server": "cd apps/slackbot-proxy && yarn start:prod",
     "release-subpackages": "turbo run build --filter @growi/core --filter @growi/pluginkit && changeset publish",
+    "release-subpackages:next": "turbo run build --filter @growi/core --filter @growi/pluginkit && changeset version --snapshot next && changeset publish --tag next",
     "version": "yarn version --no-git-tag-version --preid=RC"
   },
   "dependencies": {