Support sparse dots in GemmFusionAutotuner pass
Support sparse dots in GemmFusionAutotuner pass

1) Add `allow_cublas` flag and set it to false for sparse dots (we cannot run cublas for reference, as it doesn't support sparsity).
2) Make sure the configs that are not supported by the codegen are excluded. Specifically, if there are more threads than metadata values, it'd fail.
3) For deviceless compilations, apply the `ReduceTileSizes` to the default config, as otherwise it produces an incorrect config for sparse dots (too many threads).
