`cmake-kits.json` synchronization problem

When a devcontainer is started, both the `qt-cpp` and the `CMake` extension try to modify `cmake-kits.json`. This creates a race condition. To be more specific, sometimes `qt-cpp` generates Qt kits before the `CMake` extension starts to watch `cmake-kits.json`.
In this situation, Qt kits are overwritten by the `CMake` extension instead of being kept.

Possible Solution:
`qt-cpp` should detect if it is run inside a devcontainer and start scanning kits from the CMake extension explicitly, like the Windows usage.