devtest: continuous CI for 1-GPU ROCm pytest off fork branches
- Clone XLA from magaonka-amd/xla@devtest instead of openxla/xla HEAD
- Restrict wheel_tests_continuous to the 1-GPU ROCm pytest:
build only py3.11 wheels, single linux-x86-64-1gpu-amd runner,
disable the ROCm bazel job
Base = clean jax-ml/jax main; XLA devtest = clean openxla/xla main.
