[MODEL] Add support for Zamba2 models (#13185)

Signed-off-by: Yury Tokpanov <yury@zyphra.com>
Signed-off-by: Quentin Anthony <qganthony@yahoo.com>
Co-authored-by: Quentin Anthony <qganthony@yahoo.com>
Co-authored-by: Tyler Michael Smith <tysmith@redhat.com>
Co-authored-by: Cyrus Leung <cyrus.tl.leung@gmail.com>

vllm/model_executor/models/bamba.py

@@ -38,8 +38,6 @@ from .utils import (is_pp_missing_parameter,
                     make_empty_intermediate_tensors_factory, make_layers,
                     maybe_prefix)
 
-KVCache = Tuple[torch.Tensor, torch.Tensor]
-
 
 class BambaMLP(nn.Module):