[P/D][main]Offline the llmdatadist connector related parts of the code and files. (#4780)

### What this PR does / why we need it?
As support for the mooncake connector is now available, the llmdatadist
connector is no longer being maintained, so the llmdatadist-related
files need to be retired.

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
By ci

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: wangxiaoteng <wangxiaoteng@huawei.com>
Signed-off-by: liziyu <liziyu16@huawei.com>
Co-authored-by: liziyu <liziyu16@huawei.com>

tests/e2e/nightly/multi_node/config/multi_node_config.py

@@ -127,9 +127,6 @@ class MultiNodeConfig:
 
         master_ip = self.master_ip
         if self.disaggregated_prefill:
-            self.envs[
-                "DISAGGREGATED_PREFILL_RANK_TABLE_PATH"] = self.disaggregated_prefill.get(
-                    "ranktable_path")
             if self.cur_index < self.decode_start_index:
                 # For prefiller nodes, use the default master ip(index==0) as DP master
                 master_ip = self.master_ip