[bugfix]remove metrics middleware (#5332)

Author: xiaolei373

fastdeploy/entrypoints/openai/api_server.py

@@ -58,7 +58,6 @@
 from fastdeploy.entrypoints.openai.utils import UVICORN_CONFIG, make_arg_parser
 from fastdeploy.envs import environment_variables
 from fastdeploy.metrics.metrics import get_filtered_metrics
-from fastdeploy.metrics.metrics_middleware import PrometheusMiddleware
 from fastdeploy.metrics.trace_util import (
     fd_start_span,
     inject_to_metadata,
@@ -255,9 +254,6 @@ async def lifespan(app: FastAPI):
 if tokens := [key for key in (args.api_key or env_tokens) if key]:
     app.add_middleware(AuthenticationMiddleware, tokens)
 
-# add middleware for http metrics
-app.add_middleware(PrometheusMiddleware)
-
 
 @asynccontextmanager
 async def connection_manager():