jax

09d903fc - Install SciPy from its source (head) to test against Python 3.14.0b1

Install SciPy from its source (head) to test against Python 3.14.0b1 Current SciPy releases don't support Python 3.14, and building from source will resolve compatibility issues introduced by the new Python version: https://github.com/jax-ml/jax/actions/runs/15678323189/job/44163705784. PiperOrigin-RevId: 772113604