[CI/Build] Update Dockerfile install+deploy image to ubuntu 22.04 (#9130)

Co-authored-by: DarkLight1337 <tlleungac@connect.ust.hk>

Dockerfile

@@ -144,7 +144,7 @@ RUN --mount=type=cache,target=/root/.cache/pip \
 #################### DEV IMAGE ####################
 #################### vLLM installation IMAGE ####################
 # image with vLLM installed
-FROM nvidia/cuda:${CUDA_VERSION}-base-ubuntu20.04 AS vllm-base
+FROM nvidia/cuda:${CUDA_VERSION}-base-ubuntu22.04 AS vllm-base
 ARG CUDA_VERSION=12.4.1
 ARG PYTHON_VERSION=3.12
 WORKDIR /vllm-workspace