update proto file to the latest in vllm

[waleedqk]

Picking up the latest generation.proto from vllm

Built from:

grpcio                     1.64.1
grpcio-health-checking     1.62.2
grpcio-reflection          1.62.2
grpcio-tools               1.64.1

[gabe-l-hart]

One little NIT about the formatting of generation.proto. If those empty whitespace lines (and also the extra newlines at the end) are coming directly from the vllm version (which I don't think they are looking at it directly), then we can keep them, but if now, I'd like a clean exact copy here.

[gabe-l-hart]

Total NIT, but does this file include these empty whitespace lines in vllm? I really dislike having them, but if this is a straight cp from vllm without any modifications, that's probably better. It may also be good to write a script that does this generation.proto update in place.

[gabe-l-hart]

I've confirmed that this does not include any breaking changes

[gabe-l-hart]

Looks good!