Simplify GPU admonition text

Author: mmcky

lectures/_admonition/gpu.md

@@ -1,11 +1,5 @@
 ```{admonition} GPU
 :class: warning
 
-This lecture is accelerated via [hardware](status:machine-details) that has access to a GPU and targets JAX for GPU programming.
-
-Free GPUs are available on Google Colab.
-To use this option, please click on the play icon top right, select Colab, and set the runtime environment to include a GPU.
-
-Alternatively, if you have your own GPU, you can follow the [instructions](https://github.com/google/jax) for installing JAX with GPU support.
-If you would like to install JAX running on the `cpu` only you can use `pip install jax[cpu]`
+This lecture is designed to run on a GPU. To use Google Colab's free GPUs, click the play icon top right, select Colab, and set the runtime to include a GPU. For local GPU setup, see the [JAX installation guide](https://github.com/google/jax).
 ```