Create a two-device runner scale set for sharktank test

[yamiyysu]

Rob set up tests that utilize two MI300 devices. This issue is to set up the runner to run the test.
Context from Rob: GPU wise we either need two w7900 or mi300. The basic workflow is already checked in here
We can reconfigure the environment variable for either piece of hardware.

I had a fork before pkgci_test_sharktank.yml but