Change from thread_priority.hpp to realtime_helpers.hpp (backport #1829)

[mergify]

Change from the deprecated thread_priority.hpp to new realtime_helpers.hpp

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This is an automatic backport of pull request #1829 done by Mergify.

[mergify]

Cherry-pick of 8fa60db has failed:

On branch mergify/bp/iron/pr-1829
Your branch is up to date with 'origin/iron'.

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Unmerged paths:
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	both modified:   controller_manager/src/ros2_control_node.cpp

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 62.31%. Comparing base (e4d1450) to head (b1d42cb).
Report is 1 commits behind head on iron.

Additional details and impacted files

@@            Coverage Diff             @@
##             iron    #1867      +/-   ##
==========================================
+ Coverage   62.28%   62.31%   +0.02%     
==========================================
  Files         112      112              
  Lines       13137    13137              
  Branches     8911     8912       +1     
==========================================
+ Hits         8183     8186       +3     
- Misses        962      963       +1     
+ Partials     3992     3988       -4     

Flag	Coverage Δ
unittests	62.31% <ø> (+0.02%)	⬆️

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Files with missing lines	Coverage Δ
controller_manager/src/ros2_control_node.cpp	68.88% <ø> (ø)

... and 3 files with indirect coverage changes