Remove Post(const LocalHandle& ready_fence, const Meta& meta)

This function is useless for now and in foreseeable future because user
metadata will be in ashmen, and there won't be custom metadata on the
Post() interface.

Tested on master branch with Marlin
and oc-dr1-daydream-dev branch with Vega
Test: buffer_hub-test buffer_hub_queue-test
buffer_hub_queue_producer-test dvr_api-test dvr_buffer_queue-test
Bug: 70048475

Change-Id: I58590e4a1358afdf784968bac65a48b98fd0f4fc