Use Clock instead of Rate for backward compatibility of rolling

[saikishor]

The recently merged : #1810 breaks the backward compatibility of rolling in Humble, as the Humble rclcpp doesn't have the implementation of the Rate using Clock -> https://github.com/ros2/rclcpp/blob/humble/rclcpp/include/rclcpp/rate.hpp#L115

This PR proposes a fix by using the Clock's sleep_until method which is backward compatible and works the same

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 87.99%. Comparing base (93a2a68) to head (b0d35fb).
Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
controller_manager/src/ros2_control_node.cpp	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1864      +/-   ##
==========================================
- Coverage   88.01%   87.99%   -0.03%     
==========================================
  Files         121      121              
  Lines       12410    12410              
  Branches     1108     1108              
==========================================
- Hits        10923    10920       -3     
- Misses       1083     1085       +2     
- Partials      404      405       +1     

Flag	Coverage Δ
unittests	87.99% <50.00%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
controller_manager/src/ros2_control_node.cpp	77.77% <50.00%> (-0.49%)	⬇️

... and 1 file with indirect coverage changes

[bmagyar]

To avoid this in the future, I think we should add a semi-binary job for Humble too for the master branch.

[christophfroehlich]

To avoid this in the future, I think we should add a semi-binary job for Humble too for the master branch.

I would have done this already, but someone argued against it 😉