Make sure ROS2 ament exports the g3log_ros dependency

[impala454]

Hi, long time user of this library at Nauticus Robotics and just sniff testing the latest and found this minor issue with a fresh clone/build. This line helps ament tell downstream consumers of liboculus where to find g3log_ros.

[amarburg]

Thanks! I'll verify on this end.

In my dev branches, I'm migrating to spdlog as a rosdep-able dependency, actually it's a two-part change:

1. Use spdlog / fmt for logging in the library
2. Define an default internal logger with no sinks so the library is silent by default. Wrap-around applications can then assign a logger to control output from the lib.

Interested in your hot take on that change.