macOS requires setting of RPATH in executable solver

On macOS, and I suppose other BSD systems, one has to specify the `RPATH` for any third-party library used during the building of the solver because these libraries may be installed in various non-standard locations e.g. when using the Spack package manager to build the third-party libraries for `code_saturne`. In order to make this work I modified file `python/code_saturne/base/cs_case_domain.py` so that after the building of the solver is completed the code calls the `install_name_tool `utility that macOS has to add the required RPATHs to the executable.

The modification is changing the code starting from line 1007 checking if the platform is macOS and then calling this utility for each library path needed (only unique values should be used).

The modified file is attached to this issue report and it works properly on my system.

[cs_case_domain.py.zip](https://github.com/user-attachments/files/18508964/cs_case_domain.py.zip)

从 python/code_saturne/base/cs_case_domain.py 的第 1007 行附近开始，这里是 solver 构建完成的位置。检查所附修改以及 macOS 的 install_name_tool 工具，包括如何收集和去重所需的库路径。完成标准是：构建出的 solver 为安装在 macOS 非标准位置的第三方库包含所需的 RPATHs。

由索引模型根据 Issue 内容生成。