Run deploys to npm whenever a new tag is pushed to a stable branch (#19742)

Summary:
This has been tested in `0.56-stable` and was used to deploy the `0.56.0-rc.2` release.
Pull Request resolved: https://github.com/facebook/react-native/pull/19742

Differential Revision: D9071349

Pulled By: hramos

fbshipit-source-id: 6bccbe4a56cb080bd7d75c1f622168e462fb4c86

.circleci/config.yml

@@ -679,7 +679,8 @@ workflows:
       - publish_npm_package:
           filters:
             branches:
-              ignore: /.*/
+              only:
+                - /.*-stable/
             tags:
               only: /v[0-9]+(\.[0-9]+)*(\-rc(\.[0-9]+)?)?/
           requires: