[JAX] Do not build the GPU or TPU extensions if not enabled in the JAX build.
[JAX] Do not build the GPU or TPU extensions if not enabled in the JAX build.

There's no point building extensions that cannot be used, and they sometimes cause problems (e.g., TPU support on Windows builds).

Fixes https://github.com/google/jax/issues/10687

PiperOrigin-RevId: 449287997

google/jax,google/jax,google/jax,google/jax