Revert "Manual engine roll to update format of `compileExpression` RPC response (#59717)" (#59774)

Failing dev/integration_tests/ui/test_driver/keyboard_resize_test.dart
Also timing out on new_gallery_ios__transition_perf

This reverts commit c7a37c72.

bin/internal/engine.version

-a5a0a6014ab3c84e67e1a6d8bca97e0b02fbdd00
+965fbbed1776545ee681cb57f3fb1d0c2000bbcb

packages/flutter_tools/lib/src/vmservice.dart

@@ -266,7 +266,9 @@ vm_service.VmService setUpVmService(
           isStatic);
       return <String, dynamic>{
         'type': 'Success',
-        'result': <String, dynamic>{'kernelBytes': kernelBytesBase64},
+        'result': <String, dynamic>{
+          'result': <String, dynamic>{'kernelBytes': kernelBytesBase64},
+        },
       };
     });
     vmService.registerService('compileExpression', 'Flutter Tools');