[.gitignore] Add bundle script

No need to commit this in the repo, but keeping this locally helps with
building the feedback repo.

ghstack-source-id: 28f08992b1ab856567a5338af07e12ac820a7298
Pull Request resolved: https://github.com/facebook/react-forget/pull/2854

compiler/.gitignore

@@ -20,3 +20,5 @@ dist
 !packages/playground/.vscode
 .spr.yml
 testfilter.txt
+
+bundle-oss.sh