Use MTLHazardTrackingMode.untracked for Resources

[cwfitzgerald]

Currently we rely on the metal runtime to track and generate all the barriers for our code. This is wasteful as we already have all the barrier information available to the hal. We should set MTLHazardTrackingMode.untracked on all textures/buffers then call the various barrier functions to prevent races.

Related to #3109 due to default heap behavior.