[Kernel] add l2norm triton kernel (#4595)

### What this PR does / why we need it?
This pull request introduces an L2 normalization kernel implemented in
Triton, specifically optimized for Ascend NPUs.
### Does this PR introduce _any_ user-facing change?
No, this PR does not introduce any user-facing changes.
### How was this patch tested?

- vLLM version: v0.13.0
- vLLM main:
bc0a5a0c08

---------

Signed-off-by: Ascendyh <hw7osiris@outlook.com>
Co-authored-by: Mengqing Cao <cmq0113@163.com>

.github/workflows/_e2e_test.yaml

@@ -103,6 +103,7 @@ jobs:
           # We found that if running aclgraph tests in batch, it will cause AclmdlRICaptureBegin error. So we run
           # the test separately.
 
+          pytest -sv --durations=0 tests/e2e/nightly/ops/triton/
           pytest -sv --durations=0 tests/e2e/singlecard/test_completion_with_prompt_embeds.py
           pytest -sv --durations=0 tests/e2e/singlecard/test_aclgraph_accuracy.py
           pytest -sv --durations=0 tests/e2e/singlecard/test_async_scheduling.py