[Chore] Replace all base64 usages with faster pybase64 package (#37290)

Signed-off-by: Isotr0py <mozf@mail2.sysu.edu.cn>

examples/pooling/plugin/prithvi_geospatial_mae_io_processor.py

@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
-import base64
 import os
 
+import pybase64 as base64
 import torch
 
 from vllm import LLM