clean duplicate code (#7512)

Author: habaohaba

python/sglang/srt/disaggregation/prefill.py

@@ -93,8 +93,6 @@ def __init__(
         self.gpu_id = gpu_id
         self.bootstrap_port = bootstrap_port
         self.queue: List[Req] = []
-        self.pp_rank = pp_rank
-        self.pp_size = pp_size
         self.gloo_group = gloo_group
         self.max_total_num_tokens = max_total_num_tokens
         self.scheduler = scheduler