[Models] Improve iteration over layers (#19497)

Signed-off-by: Lukas Geiger <lukas.geiger94@gmail.com>

vllm/model_executor/models/seed_oss.py

@@ -23,6 +23,7 @@
 # limitations under the License.
 """Inference-only SeedOss model compatible with HuggingFace weights."""
 from collections.abc import Iterable
+from itertools import islice
 from typing import Optional, Union
 
 import torch
@@ -340,7 +341,7 @@ class SeedOssModel(nn.Module):
             assert intermediate_tensors is not None
             hidden_states = intermediate_tensors["hidden_states"]
             residual = intermediate_tensors["residual"]
-        for layer in self.layers[self.start_layer:self.end_layer]:
+        for layer in islice(self.layers, self.start_layer, self.end_layer):
             hidden_states, residual = layer(
                 positions,
                 hidden_states,