[master]{ros2} ament_cmake: add python configurations for class-target

[jiaxshi]

Add target configurations for fixing wrong PYTHONSOABI of python c libraries in rosbag2_py.

Issue: runtime error of rosbag2

root@qcs6490-rb3gen2-core-kit:/# ros2 bag -h
Failed to load entry point 'burst': No module named 'rosbag2_py._compression_options'
Failed to load entry point 'convert': No module named 'rosbag2_py._compression_options'
Failed to load entry point 'info': No module named 'rosbag2_py._compression_options'
Failed to load entry point 'play': No module named 'rosbag2_py._compression_options'
Failed to load entry point 'record': No module named 'rosbag2_py._compression_options'
Failed to load entry point 'reindex': No module named 'rosbag2_py._compression_options'
usage: ros2 bag [-h] Call `ros2 bag <command> -h` for more detailed usage. ...

Root Cause

Because the target configuration is missing, the Python interpreter reads PYTHON_SOABI from the host (x86_64), which results in incorrectly named(x86_64) libraries.

ls /usr/ros/jazzy/lib/python3.14/site-packages/rosbag2_py/
__init__.py                                           _reader.pyi
__init__.pyi                                          _reindexer.cpython-314-x86_64-linux-gnu.so
__pycache__                                           _reindexer.pyi
_compression_options.cpython-314-x86_64-linux-gnu.so  _storage.cpython-314-x86_64-linux-gnu.so
_compression_options.pyi                              _storage.pyi
_info.cpython-314-x86_64-linux-gnu.so                 _transport.cpython-314-x86_64-linux-gnu.so
_info.pyi                                             _transport.pyi
_message_definitions.cpython-314-x86_64-linux-gnu.so  _writer.cpython-314-x86_64-linux-gnu.so
_message_definitions.pyi                              _writer.pyi
_reader.cpython-314-x86_64-linux-gnu.so               py.typed

[RicardoM17]

Tested on my side and it works

Would love to see this merged :)