upgrade to 0.18.0 (#7502)

### What this PR does / why we need it?
1. upgrade to 0.18.0
2. ensure kernel_block_sizes is int for Eagle drafter
### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: v0.17.0
- vLLM main:
8b6325758c

---------

Signed-off-by: Meihan-chen <jcccx.cmh@gmail.com>
Signed-off-by: hfadzxy <starmoon_zhang@163.com>
Co-authored-by: hfadzxy <starmoon_zhang@163.com>

.github/workflows/_e2e_nightly_single_node.yaml

@@ -39,7 +39,7 @@ on:
       vllm_version:
         required: false
         type: string
-        default: "v0.17.0"
+        default: "v0.18.0"
       is_pr_test:
         required: true
         type: boolean