Update TFRT dependency to use revision
Update TFRT dependency to use revision
http://github.com/tensorflow/runtime/commit/8b26d736c7e05a4a4a2fdb099c882c7c0010c8ae.

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/10638 from jaro-sevcik:host-allocation-custom-call 0f78007475921031549c8555ad56ed8903efe6cb
