Remove deprecated cmake include

Signed-off-by: Nordmann Arne (CR/ADT3) <arne.nordmann@de.bosch.com>

Author: norro

system_modes/CMakeLists.txt

@@ -148,7 +148,6 @@ if(BUILD_TESTING)
   endif()
 
   # Launch Tests
-  find_package(ament_cmake_pytest REQUIRED)
   find_package(launch_testing_ament_cmake REQUIRED)
   set(launch_tests
     "two_lifecycle_nodes"           # Mode Manager with Lifecycle Nodes