[main][misc]change default capture size for Qwen3-MoE when using full dp (#4199)

### What this PR does / why we need it?
Currently, the default `cudagraph_capture_size` in vLLM is `[1, 2, 4 ,8
,16 ,24 ,... , max_capture_size]`. However, this is not always the best
choice on different situations. This PR aims to change the default
setting when running Qwen3-MoE on full dp (`dp_size > 1` && `tp_size ==
1`) setting, which is usually applied in Large-Scale EP.
old :
`[1, 2, 4 ,8 ,16 ,24 ,... , max_capture_size]`
new:
`[1, 2, 5 ,10 ,15, 16 ,24 ,... , max_capture_size]`
This is mainly because the performance of `_npu_paged_attention` op
degrades dramatically on old settings. We hope to provide better
performance if users do not set specific `cudagraph_capture_size`.
### Does this PR introduce _any_ user-facing change?
The default `cudagraph_capture_size` is modified in above cases.
However, if `cudagraph_capture_size` has already set by users, this PR
won't have any influence on this.

### How was this patch tested?

- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

---------

Signed-off-by: Angazenn <supperccell@163.com>

tests/ut/test_platform.py

@@ -330,6 +330,7 @@ class TestNPUPlatform(TestBase):
         )
 
     @patch("vllm_ascend.utils.is_310p", return_value=False)
+    @patch("vllm_ascend.utils.update_default_aclgraph_sizes")
     @patch("vllm_ascend.ascend_config.check_ascend_config")
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch(
@@ -337,7 +338,8 @@ class TestNPUPlatform(TestBase):
     )
     def test_check_and_update_config_unsupported_compilation_level(
             self, mock_init_recompute, mock_init_ascend, mock_check_ascend,
-            mock_is_310p):
+            mock_update_default, mock_is_310p):
+        mock_update_default.return_value = MagicMock()
         mock_init_ascend.return_value = TestNPUPlatform.mock_vllm_ascend_config(
         )
         vllm_config = TestNPUPlatform.mock_vllm_config()
@@ -410,6 +412,7 @@ class TestNPUPlatform(TestBase):
             )
 
     @patch("vllm_ascend.utils.is_310p", return_value=False)
+    @patch("vllm_ascend.utils.update_default_aclgraph_sizes")
     @patch("vllm_ascend.ascend_config.check_ascend_config")
     @patch("vllm_ascend.ascend_config.init_ascend_config")
     @patch(
@@ -417,7 +420,8 @@ class TestNPUPlatform(TestBase):
     )
     def test_check_and_update_config_torchair_enabled_compilation(
             self, mock_init_recompute, mock_init_ascend, mock_check_ascend,
-            mock_is_310p):
+            mock_update_default, mock_is_310p):
+        mock_update_default.return_value = MagicMock()
         mock_ascend_config = TestNPUPlatform.mock_vllm_ascend_config()
         mock_ascend_config.torchair_graph_config.enabled = True
         mock_init_ascend.return_value = mock_ascend_config