[sparsity] rename `sparsity_pattern` to `sparse_block_shape` (#59898)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59898
In `weight_norm_sparsifier`, the name of the argument `sparsity_pattern` is not intuitive for an argument describing the shape of the sparse block. It has been changed to `sparse_block_shape`.
Test Plan:
`buck test mode/dev-nosan //caffe2/test:ao -- TestWeightNormSparsifier`
https://pxl.cl/1LhRM
Reviewed By: z-a-f
Differential Revision: D29077045
fbshipit-source-id: 0cf9c5387d41ca8e839ee050d71f4fe477374143
