Disabling a no-unreachable lint error (#9300)

src/renderers/shared/fiber/ReactFiberScheduler.js

@@ -687,6 +687,7 @@ module.exports = function<T, P, I, TI, PI, C, CX, PL>(
 
     // Without this explicit null return Flow complains of invalid return type
     // TODO Remove the above while(true) loop
+    // eslint-disable-next-line no-unreachable
     return null;
   }