Update engines to node >=10 (#28174)

Summary:
v8 dropped out of LTS support, updating the package.json engines to node v10.

## Changelog

[General] [Changed] - Bump supported Node engines to >= 10
Pull Request resolved: https://github.com/facebook/react-native/pull/28174

Reviewed By: cpojer

Differential Revision: D20107977

Pulled By: hramos

fbshipit-source-id: 795cce79eb32f34e19d20bb8684b898b26e07228

package.json

@@ -9,7 +9,7 @@
     "url": "git@github.com:facebook/react-native.git"
   },
   "engines": {
-    "node": ">=8.3"
+    "node": ">=10"
   },
   "jest-junit": {
     "outputDirectory": "reports/junit",