fix: add missing index.flow.js file to out-of-tree-platforms package

Author: okwasniewski

packages/out-of-tree-platforms/src/index.flow.js

@@ -0,0 +1,5 @@
+if (!process.env.BUILD_EXCLUDE_BABEL_REGISTER) {
+  require('../../../scripts/build/babel-register').registerForMonorepo();
+}
+
+export * from './getPlatformResolver';