test only smaller block_k for mm_plus_mm (#96385)
Trim number of tested mm_plus_mm configs to work around https://github.com/openai/triton/issues/1298
Pull Request resolved: https://github.com/pytorch/pytorch/pull/96385
Approved by: https://github.com/bertmaher, https://github.com/jansel
Author
Natalia Gimelshein
