Remove 'toppra' dependency conditions in package.xml (#263)

Author: sea-bass

roboplan_toppra/package.xml

@@ -12,9 +12,7 @@
 
   <depend>nanobind-dev</depend>
   <depend>roboplan</depend>
-  <!-- TODO: Update this as toppra gets released on more ROS distros. -->
-  <!-- If not yet available, there is a source build fallback via FetchContent. -->
-  <depend condition="$ROS_DISTRO == humble or $ROS_DISTRO == lyrical">toppra</depend>
+  <depend>toppra</depend>
 
   <test_depend>ament_cmake_gtest</test_depend>
   <test_depend>roboplan_example_models</test_depend>