Remove TPU_LIBRARY_PATH from legacy TPU CI (#7968)

Author: will-cromar

test/tpu/xla_test_job.yaml

@@ -46,8 +46,6 @@ spec:
  pip install torch_xla[pallas] -f https://storage.googleapis.com/jax-releases/jax_nightly_releases.html -f https://storage.googleapis.com/jax-releases/jaxlib_nightly_releases.html
 
  cd /src/pytorch/xla
- # TODO: pallas test requires JAX, now we need to explicitly set TPU_LIBRARY_PATH for JAX, need a permanent fix.
- TPU_LIBRARY_PATH=/usr/local/lib/python3.10/site-packages/torch_xla/lib/libtpu.so test/tpu/run_tests.sh
  volumeMounts:
  - mountPath: /dev/shm
  name: dshm