Only use /dev/shm/bazel output_base for TPU presubmit test jobs.
Non-presubmit jobs running full test suites run out of /dev/shm space when Bazel uses /dev/shm as output_base. Only TPU v6e runners, used for presubmits, are configured with enough /dev/shm space.
PiperOrigin-RevId: 956177884
