Remove nav2_loopback_sim dependency on transforms3d. (#4738)

The package never uses it, so don't declare it.

Signed-off-by: Chris Lalancette <[email protected]>

nav2_loopback_sim/package.xml

@@ -12,7 +12,6 @@
   <exec_depend>nav_msgs</exec_depend>
   <exec_depend>tf_transformations</exec_depend>
   <exec_depend>tf2_ros</exec_depend>
-  <exec_depend>python3-transforms3d</exec_depend>
 
   <test_depend>ament_copyright</test_depend>
   <test_depend>ament_flake8</test_depend>