[CI] Remove forbidden slash (vllm-project#27112)

Signed-off-by: NickLucche <nlucches@redhat.com>

Author: NickLucche

.buildkite/test-pipeline.yaml

@@ -1085,7 +1085,7 @@ steps:
   commands:
     - bash weight_loading/run_model_weight_loading_test.sh -c weight_loading/models-large.txt
 
-- label: NixlConnector P/D accuracy tests (Distributed) # 30min
+- label: NixlConnector PD accuracy tests (Distributed) # 30min
   timeout_in_minutes: 30
   working_dir: "/vllm-workspace/tests"
   num_gpus: 4