fix: update publishing packages tag message prefix (facebook#36348)

Summary:
Pull Request resolved: facebook#36348

Changelog: [Internal]

Turns out that Phabricator strips `@` symbol from `@...` tags when exports commits to GitHub. Proposing to use `#` instead.

#publish-packages-to-npm

Reviewed By: cortinico

Differential Revision: D43712415

fbshipit-source-id: 86fc728eb0cb63afb6a9fe592a9ae998da2ce2e4

Author: hoxyq

scripts/monorepo/constants.js

@@ -8,6 +8,6 @@
  * @format
  */
 
-const PUBLISH_PACKAGES_TAG = '@publish-packages-to-npm';
+const PUBLISH_PACKAGES_TAG = '#publish-packages-to-npm';
 
 module.exports = {PUBLISH_PACKAGES_TAG};