`ament_target_dependencies` deprecation notice

This is a very minor issue, but `ament_target_dependencies` is still used in the `rcl` CMakeLists.txt fork because of the patch, and thus generates a warning upon building.

https://github.com/micro-ROS/rcl/blob/e8738a46bc2804485cf2f03ec8344cfc20e6a8d8/rcl/CMakeLists.txt#L118-L128

Start with the linked rcl/CMakeLists.txt section at lines 118-128 and inspect how the patch leaves ament_target_dependencies in use. Build the affected package to reproduce the deprecation warning, then verify the warning is gone after the build configuration is updated.

Written by the indexing model from the issue text.