Simplify bundled plugin setup

Summary: Stop bundling plugins into Flipper Server bundles. In later diffs, we will start building all plugins even in dev mode which removes the need to bundle them.

Reviewed By: lblasa

Differential Revision: D39276249

fbshipit-source-id: 091405cfcf58aa7e1bd2b382da40f8d9841ae6b1

desktop/scripts/start-flipper-server-dev.tsx

@@ -186,10 +186,9 @@ async function startWatchChanges() {
   }
   await prepareDefaultPlugins(
     process.env.FLIPPER_RELEASE_CHANNEL === 'insiders',
-    true,
   );
-  await buildHeadlessPlugins(true);
   await buildServerAddOns(true);
+  await buildHeadlessPlugins(true);
 
   await ensurePluginFoldersWatchable();
   // builds and starts