remove middleware

Author: guglielmo-san

src/a2a/server/routes/agent_card_routes.py

@@ -5,22 +5,19 @@
 
 
 if TYPE_CHECKING:
-    from starlette.middleware import Middleware
     from starlette.requests import Request
     from starlette.responses import JSONResponse, Response
     from starlette.routing import Route
 
     _package_starlette_installed = True
 else:
     try:
-        from starlette.middleware import Middleware
         from starlette.requests import Request
         from starlette.responses import JSONResponse, Response
         from starlette.routing import Route
 
         _package_starlette_installed = True
     except ImportError:
-        Middleware = Any
         Route = Any
         Request = Any
         Response = Any

src/a2a/server/routes/jsonrpc_routes.py

@@ -5,18 +5,15 @@
 
 
 if TYPE_CHECKING:
-    from starlette.middleware import Middleware
     from starlette.routing import Route, Router
 
     _package_starlette_installed = True
 else:
     try:
-        from starlette.middleware import Middleware
         from starlette.routing import Route, Router
 
         _package_starlette_installed = True
     except ImportError:
-        Middleware = Any
         Route = Any
         Router = Any