[CI]fix nightly multi node test error for wait for pod ready (#6675)

### What this PR does / why we need it?
Fixes the issue where nightly multi-node tests hang during the "wait for
pod ready" stage due to strict shell mode.

### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: v0.15.0
- vLLM main:
13397841ab

Signed-off-by: MrZ20 <2609716663@qq.com>

tests/e2e/nightly/multi_node/scripts/run.sh

@@ -14,7 +14,11 @@ export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATH
 # cann and atb environment setup
 source /usr/local/Ascend/ascend-toolkit/set_env.sh
 source /usr/local/Ascend/cann-8.5.0/share/info/ascendnpu-ir/bin/set_env.sh
+
+set +eu
 source /usr/local/Ascend/nnal/atb/set_env.sh
+set -eu
+
 # Home path for aisbench
 export BENCHMARK_HOME=${WORKSPACE}/vllm-ascend/benchmark