OptionalacceleratorTotal number of accelerators across all nodes. Must be a positive
multiple of the per-node accelerator count encoded in accelerator_type.
For example, GPU_8xH100 with accelerator_count: 16 allocates 2 nodes
(8 GPUs per node).
OptionalacceleratorHardware accelerator type (for example, GPU_1xA10 or GPU_8xH100).
The number of accelerators per node is encoded in the enum value —
GPU_8xH100 means 8 H100 GPUs per node.
ComputeSpec: compute configuration — accelerator type and total accelerator count across all nodes.