Float8DynamicActivationFloat8SemiSparseWeightConfig is being deprecated

[jcaip]

We added a custom config, Float8DynamicActivationFloat8SemiSparseWeightConfig, for fp8 + 2:4 sparsity in the past, but following our migration off of AQT (#3361) we now plan to express sparsity as a packing format.

Instead, this functionality will be exposed via packing format instead:

Before:

Float8DynamicActivationFloat8SemiSparseWeightConfig()

After:

Float8DynamicActivationFloat8WeightConfig(
    packing_format=Float8PackingFormat.SPARSE_CUTLASS,
    granularity=PerRow(),
),