Remove export of wrench_transformer_node (backport #2069)

[mergify]

It doesn't make sense to export an executable; this is causing issues when you add the packages as a dependency and use ament_auto

--- stderr: robot_control
CMake Error at /opt/ros/humble/share/ament_cmake_gmock/cmake/ament_add_gmock.cmake:69 (add_executable):
  Target "test_transmission_manager" links to target
  "force_torque_sensor_broadcaster::wrench_transformer_node" but the target
  was not found.  Perhaps a find_package() call is missing for an IMPORTED
  target, or an ALIAS target is missing?
Call Stack (most recent call first):
  /opt/ros/humble/share/ament_cmake_gmock/cmake/ament_add_gmock.cmake:52 (_ament_add_gmock)
  /opt/ros/humble/share/ament_cmake_auto/cmake/ament_auto_add_gmock.cmake:45 (ament_add_gmock)
  CMakeLists.txt:21 (ament_auto_add_gmock)
CMake Error at /opt/ros/humble/share/ament_cmake_gtest/cmake/ament_add_gtest_executable.cmake:50 (add_executable):
  Target "test_load_robot_control" links to target
  "force_torque_sensor_broadcaster::wrench_transformer_node" but the target
  was not found.  Perhaps a find_package() call is missing for an IMPORTED
  target, or an ALIAS target is missing?
Call Stack (most recent call first):
  /opt/ros/humble/share/ament_cmake_gtest/cmake/ament_add_gtest_executable.cmake:37 (_ament_add_gtest_executable)
  /opt/ros/humble/share/ament_cmake_auto/cmake/ament_auto_add_gtest.cmake:71 (ament_add_gtest_executable)
  CMakeLists.txt:26 (ament_auto_add_gtest)
CMake Error at /opt/ros/humble/share/ament_cmake_gmock/cmake/ament_add_gmock.cmake:69 (add_executable):
  Target "test_robot_control" links to target
  "force_torque_sensor_broadcaster::wrench_transformer_node" but the target
  was not found.  Perhaps a find_package() call is missing for an IMPORTED
  target, or an ALIAS target is missing?
Call Stack (most recent call first):
  /opt/ros/humble/share/ament_cmake_gmock/cmake/ament_add_gmock.cmake:52 (_ament_add_gmock)
  /opt/ros/humble/share/ament_cmake_auto/cmake/ament_auto_add_gmock.cmake:45 (ament_add_gmock)
  CMakeLists.txt:72 (ament_auto_add_gmock)

For example: https://github.com/ros2/geometry2/blob/9462cec08e5d01fcb54cfdf5abbcde0c31029ae8/tf2_ros/CMakeLists.txt#L115-L123

---

This is an automatic backport of pull request #2069 done by Mergify.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.59%. Comparing base (e1fd7d5) to head (71bb4b1).
⚠️ Report is 1 commits behind head on humble.

Additional details and impacted files

@@           Coverage Diff           @@
##           humble    #2070   +/-   ##
=======================================
  Coverage   67.59%   67.59%           
=======================================
  Files         126      126           
  Lines       14376    14376           
  Branches     9144     9144           
=======================================
  Hits         9717     9717           
- Misses       1402     1408    +6     
+ Partials     3257     3251    -6     

Flag	Coverage Δ
unittests	67.59% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.
see 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.