don't codegen redundant 'final'

Author: jjergus

src/RouterCodegenBuilder.hack

@@ -90,7 +90,6 @@ final class RouterCodegenBuilder<T as IncludeInUriMap> {
       ))
       ->addMethod(
         $this->cg->codegenMethod('getRoutes')
-          ->setIsFinal(true)
           ->setIsOverride(true)
           ->setReturnTypef(
             'ImmMap<\\%s, ImmMap<string, classname<\\%s>>>',

tests/examples/codegen/MySiteRouter.php

@@ -5,15 +5,15 @@
  * To re-generate this file run vendor/hhvm/hacktest/bin/hacktest
  *
  *
- * @generated SignedSource<<87e793dd3e7f67b9636fe2de5fd524d3>>
+ * @generated SignedSource<<5fc74ee3cca9f2cc0eda4d4743d264d9>>
  */
 namespace Facebook\HackRouter\CodeGen\Tests\Generated;
 
 final class MySiteRouter
   extends \Facebook\HackRouter\BaseRouter<classname<\Facebook\HackRouter\CodeGen\Tests\GetRequestExampleController>> {
 
   <<__Override>>
-  final public function getRoutes(
+  public function getRoutes(
   ): ImmMap<\Facebook\HackRouter\HttpMethod, ImmMap<string, classname<\Facebook\HackRouter\CodeGen\Tests\GetRequestExampleController>>> {
     $map = ImmMap {
       \Facebook\HackRouter\HttpMethod::GET => ImmMap {