fix: use GitHub includes instead of relative paths in react-native plugin

Relative path includes (path:../android/plugin.json) don't resolve
when the plugin is fetched from a remote GitHub source. Switch to
full GitHub plugin URLs so the react-native aggregator works as
a remote include.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: abueide

plugins/react-native/plugin.json

@@ -3,8 +3,8 @@
   "version": "0.0.2",
   "description": "Aggregates the Android and iOS Devbox plugins for React Native projects.",
   "include": [
-    "path:../android/plugin.json",
-    "path:../ios/plugin.json"
+    "github:segment-integrations/devbox-plugins?dir=plugins/android",
+    "github:segment-integrations/devbox-plugins?dir=plugins/ios"
   ],
   "packages": {
     "curl": "latest",