[CI] Add DeepSeek-V3.2 large EP nightly ci (#6378)

### What this PR does / why we need it?

Add DeepSeek-V3.2 nightly ci

Fix PD routing to exclude headless nodes when collecting
prefiller/decoder IPs

- vLLM version: v0.14.1
- vLLM main:
dc917cceb8

Signed-off-by: hfadzxy <starmoon_zhang@163.com>

.github/workflows/schedule_nightly_test_a3.yaml

@@ -95,6 +95,9 @@ jobs:
           - name: multi-node-deepseek-v3.1
             config_file_path: DeepSeek-V3.1-BF16.yaml
             size: 2
+          - name: multi-node-deepseek-v3.2-W8A8-EP
+            config_file_path: DeepSeek-V3_2-W8A8-EP.yaml
+            size: 4
     uses: ./.github/workflows/_e2e_nightly_multi_node.yaml
     with:
       soc_version: a3