[Catalog] Special instance type on Azure only holds a fractional of GPU but tagged as one whole GPU in catalog

[cblmemo]

https://learn.microsoft.com/en-us/azure/virtual-machines/nva10v5-series

Some instance type, like Standard_NV6ads_A10_v5, only holds a fractional of GPU (1/6 for Standard_NV6ads_A10_v5). The GPU memory of those instance types is also fractional (4GB for Standard_NV6ads_A10_v5). But they are tagged as one whole GPU and used as if they have 24GB GPU memory, like the following example.

skypilot/llm/qwen/serve-7b.yaml

Line 20 in 4821f70

accelerators: {L4, A10g, A10, L40, A40, A100, A100-80GB}