Remove small code duplication in CMakelists.txt for ROS2/Ament packaging #237

Job	Run time
ubuntu-latest - Env all Release	35m 44s
ubuntu-latest - Env all Debug	2m 42s
ubuntu-latest - Env all-py39 Release	1m 19s
ubuntu-latest - Env all-py39 Debug	37m 9s
macos-latest - Env all Release	1m 47s
macos-latest - Env all Debug	3m 23s
macos-latest - Env all-py39 Release	22m 36s
macos-latest - Env all-py39 Debug	25m 34s
macos-13 - Env all Release	2m 30s
macos-13 - Env all Debug	36m 33s
macos-13 - Env all-py39 Release	44m 14s
macos-13 - Env all-py39 Debug	6m 25s
windows-latest - Env all Release	1h 11m 44s
windows-latest - Env all-clang-cl Release	4m 26s
check-macos-linux-windows-pixi	3s
	4h 56m 9s

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