[FIX] convert rclcpp to chrono

[wodtko]

With a recent update of rclcpp::Rate the return value of .period() changed to rclcpp::Duration, thus, it must be converted to the std::chrono::duration used here.

ros2/rclcpp@bc43577 here are the respective changes in rclcpp

action-ros-ci-repos-supplemental: https://github.com/raw/ros2/ros2/rolling/ros2.repos

[christophebedard]

Looks good to me, thanks for updating this.

CI is using a binary installation of Rolling, so that's why it's failing. To force it to build ROS 2 from source just for this PR, you could add the following line to the PR description, and then amend + force push your commit to make CI run again:

action-ros-ci-repos-supplemental: https://github.com/raw/ros2/ros2/rolling/ros2.repos

See https://github.com/ros-tooling/action-ros-ci#Interdependent-pull-requests-or-merge-requests.

[christophebedard]

It looks like this change (i.e., API break) was unintentional. It's being fixed in ros2/rclcpp#2301.

We won't need this PR, unless they actually deprecate this one and add a new Rate::period() method that returns a Duration. Until then, I'll close this. Thanks for contributing, though!