[task] Add fused gdn gating triton kernel (#4304)

### What this PR does / why we need it?
This commit introduces a Triton-based fused GDN gating kernel for Ascend
NPU, aimed at improving performance in the Gated Delta Net workflow.
### Does this PR introduce _any_ user-facing change?
It only adds and refactors internal Triton kernels and wrappers for
Ascend. These are backend implementation details. There are no new APIs,
flags, CLI options, or behavior changes visible to end users.
### How was this patch tested?

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: Ascendyh <hw7osiris@outlook.com>

vllm_ascend/patch/__init__.py

@@ -297,3 +297,13 @@
 #    Future Plan:
 #       Remove this patch when vLLM support these operators.
 #
+#   2. `vllm.model_executor.models.qwen3_next.Qwen3NextGatedDeltaNet._forward_core`
+#    Why:
+#       The Qwen3Next GatedDeltaNet _forward_core cannot directly add custom operators.
+#    How：
+#       Add a branch in Qwen3NextGatedDeltaNet._forward_core to adapt to fused_gdn_gating_patch.
+#    Related PR (if no, explain why):
+#       https://github.com/vllm-project/vllm/pull/31002
+#    Future Plan:
+#       Remove this patch when vLLM support these operators.
+#