Remove default plugin entrypoints for hot-reloading

Summary: As we stopped bundling plugins in D39276249, we no longer need the entry points for the bundled plugins (these entry points are always going to be empty)

Reviewed By: lblasa

Differential Revision: D39307565

fbshipit-source-id: 43751fe31c8bd962677c226b27cfe52093d3f2d4

desktop/scripts/jest-setup-after.tsx

@@ -181,9 +181,6 @@ function createStubRenderHost(): RenderHost {
     restartFlipper() {},
     openLink() {},
     serverConfig: stubConfig,
-    loadDefaultPlugins() {
-      return {};
-    },
     GK(gk: string) {
       return stubConfig.gatekeepers[gk] ?? false;
     },