Deprecate resource management in GPU plugin & xpu-manager sidecar

[tkatila]

GPU Aware Scheduler's (GAS) use cases can be handled by DRA and GAS is going to be EoL'd sometime in the future. To simplify the implementation, use and deployments, we are removing the resource manager functionality from the GPU plugin.

Also deprecate xpu-manager sidecar as its data is only relevant with GAS.

Tasks:

• Add note about "last release" in the 0.32 release notes.
• Remove resource manager functionality from plugin code, deployment files, documentation etc. after 0.32 release.
• Note xpu-manager sidecar final release with 0.32
• Disable xpu-manager sidecar builds and publishes after 0.32
• Remove xpu-manager sidecar code etc. after 0.33

fyi, @uniemimu