Add MI300X Runners to AMD workflow.

[saienduri]

Description

This commit adds mi300 nodes as an option to the current amd workflow.

I tested a couple times on the AMD workflow here (https://github.com/gpu-mode/discord-cluster-manager/actions/runs/12902691574)

Checklist

Before submitting this PR, ensure the following steps have been completed:

• Run the slash command /verifyruns on your own server.
  • Run the cluster bot on your server:

    python discord-bot.py

  • Start training runs with the slash command /verifyruns.
  • Verify that the bot eventually responds with:

    ✅ All runs completed successfully!
    

    (It may take a few minutes for all runs to finish. In particular, the GitHub
    runs may take a little longer. The Modal run is typically quick.)
    For more information on running a cluster bot on your own server, see
    README.md.

[ngc92]

I don't think this is the way we want to handle multiple runners; afaics, this well always run the given code sample on both types of AMD cards. Instead, the card should be selectable by an input argument that is given to the job.

Both runners should be registered in src/discord-cluster-manager/consts.py, and
https://github.com/gpu-mode/discord-cluster-manager/blob/main/src/discord-cluster-manager/cogs/github_cog.py#L35-L40
needs to be updated

[saienduri]

Makes sense, thanks for the info! Updated github_cog but I don't think we need to touch consts.py

[msaroufim]

To merge this PR faster I'm thinking what might be easiest is just moving to only using MI300 - wdyt @saienduri

[saienduri]

Thanks for the signal @msaroufim! I updated the PR, so that it should work with card selection. Does it look good to y'all?
Here's an example run I trigged in github: https://github.com/gpu-mode/discord-cluster-manager/actions/runs/13350719364