Perhaps on newer version of debian this is no longer necessary. FWIW, the documentation already recommends installing libopenblas-dev:
sudo apt install python3-numpy python3-matplotlib libatlas-base-dev libopenblas-dev
So, you could try installing without libatlas-base-dev, perhaps? I’m unsure if that would affect very old distributions of debian, for example.
Note that until some time we did not fix Numpy version, but apparently it caused some issues in some cases, and the version was fixed. I do not think that Klipper uses any specific features that would block migration to Numpy 2.x, but I’m unsure whether this would cause any issues with some environments. Separately, this is installed via pip, does the version of debian even matter? Note that system-wide version of Numpy (installed via apt) is not fixed as per command above.