20230527
only prune to_v (so should divide to_qkv to to_qkv and to_v, and only prune to_v)
attn (1, 12, 197, 197) * pruned_v (1, 12, 197, int(64*s)) = out1 (1, 12, 197, int(64*s))
out1 rearange to out2 (1, 197, int(768*s))
out2 (1, 197, int(768*s)) * pruned mlp_fc1 (int(768*s), int(3072*s))
