### What this PR does / why we need it?
Fix the moe_forward error when setting enable_static_kernel to true.
When static kernels are enabled, the forward pass runs twice
(compilation + capture), causing moe_layer_index to overflow. Wrap the
index to prevent out-of-bounds errors.
### Does this PR introduce _any_ user-facing change?
None
### How was this patch tested?
CI passed with new added test
- vLLM version: v0.16.0
- vLLM main:
15d76f74e2
Signed-off-by: p00465316 <panchao13@huawei.com>
Co-authored-by: p00465316 <panchao13@huawei.com>