Add missing dependency rosidl_default_generators

[srmainwaring]

Resolve compilation issue caused by missing dependency.

Details

System: macOS 15.2 (Sequoia), Xcode 16.2
ROS 2: Jazzy, Rolling

The proposed change resolves the following build error:

% colcon build --symlink-install --cmake-args -DBUILD_TESTING=OFF -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_CXX_STANDARD=17 -DPython3_EXECUTABLE=$(which python3) --packages-select mav_state_machine_msgs
Starting >>> mav_state_machine_msgs
--- stderr: mav_state_machine_msgs                         
CMake Error at CMakeLists.txt:12 (rosidl_generate_interfaces):
  Unknown CMake command "rosidl_generate_interfaces".


---
Failed   <<< mav_state_machine_msgs [6.53s, exited with code 1]