[gardening] Mark test as slow

Closes: #61038
Change-Id: I877242bc4d193b6879b0882cf5a41b1a5c64d70c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/438661
Auto-Submit: Daco Harkes <[email protected]>
Reviewed-by: Tess Strickland <[email protected]>
Commit-Queue: Daco Harkes <[email protected]>
Commit-Queue: Tess Strickland <[email protected]>

Author: dcharkes

tests/ffi/ffi.status

@@ -2,6 +2,7 @@
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
+function_callbacks_structs_by_value_native_callable_generated_test: Pass, Slow # https://dartbug.com/61038
 function_callbacks_structs_by_value_test: Pass, Slow # https://dartbug.com/47304 https://dartbug.com/45007
 function_structs_by_value_generated_args_leaf_test: Pass, Slow # https://dartbug.com/47303 https://dartbug.com/45007
 function_structs_by_value_generated_args_test: Pass, Slow # https://dartbug.com/47303 https://dartbug.com/45007
@@ -110,4 +111,4 @@ callback_unwind_error_test: Crash # https://github.com/dart-lang/sdk/issues/3948
 data_not_asan_test: SkipByDesign # This test tries to allocate too much memory on purpose.
 
 [ $hot_reload || $hot_reload_rollback ]
-isolate_group_shared_callback_test: SkipSlow # shared_slow_path_triggers_gc in combination with reload makes this test very slow
+isolate_group_shared_callback_test: SkipSlow # shared_slow_path_triggers_gc in combination with reload makes this test very slow